text:
...making Linux just a little more fun!
NASA is the National Aeronautics and Space Administration for the United States government space program. The shuttle liftoff picture and the Discovery landing picture are from NASA's archives.
xplanet follows the tradition of xearth but using real imagery. I've prepared this picture using the following options:
xplanet -output lg_cover117.jpg -geometry 800x560
--background /home/heather/xplanet_bg_lg117.jpg -body
earth -longitude -20 -north orbit -config
overlay_clouds.29july05 -center +330+280 -num_times 1
I fetched the current cloudcover imagery per the instructions in /usr/share/xplanet/images/README. I decided the night image was a little too dark and made a softer one called night_mode which still shows some of the landscape. Most people don't know that you can give it any background you like instead of having it speckle the black background. Many people know that you don't have to let it pick the origin point. I started with -origin=moon which looks great but the moon wasn't visible from Florida right then, so I had to move our point of view
The starfield is actually from an ultraviolet study of the Milky Way; read a little more about our galaxy at www.astro.virginia.edu/~mwk7v/sim/mw.shtml.
I created a markerfile with only one entry in it, the latitude and longitude for Kennedy Space Center, where the current shuttle took off and will land. There are a number of groups with custom markerfiles for various purposes. If you're putting together your own, you might take a look at Dave Pietromonaco's xearth markers page since he has a Gazetteer of coordinates for many locations.
May the shuttles enjoy many more successful flights.
Heather is Linux Gazette's Technical Editor and The Answer Gang's Editor Gal.
Heather got started in computing before she quite got started learning
English. By 8 she was a happy programmer, by 15 the system administrator
for the home... Dad had finally broken down and gotten one of those personal
computers, only to find it needed regular care and feeding like any other
pet. Except it wasn't a Pet: it was one of those brands we find most
everywhere today...
Heather is a hardware agnostic, but has spent more hours as a tech in
Windows related tech support than most people have spent with their computers.
(Got the pin, got the Jacket, got about a zillion T-shirts.) When she
discovered Linux in 1993, it wasn't long before the home systems ran Linux
regardless of what was in use at work.
By 1995 she was training others in using Linux - and in charge of all the
"strange systems" at a (then) 90 million dollar company. Moving onwards, it's
safe to say, Linux has been an excellent companion and breadwinner... She
took over the HTML editing for "The Answer Guy" in issue 28, and has been
slowly improving the preprocessing scripts she uses ever since.
Here's an autobiographical filksong she wrote called
The Programmer's Daughter.
I've recently gotten a digital camera (yes, I know I'm sort of late coming into the digital revolution). This is a HP R607 and lets you add audio tags to still images.
[Lew] Kewl.
I would have thought that the audio would be a wav or mp3 file with the same name as the image, but life is never easy. I can only assume that the audio is embbedded into the jpg. I've checked, and the only files on the camera (other than some short XML files) are the jpgs.
[Lew] Yah. The JFIF format (that's the file format that "JPEG" pictures are stored in) supports a bunch of metadata. Many (I'm tempted to say most) cameras store a 'thumbnail' photo in the jpg along with the full photo. They also store camera information (make, model) and photo metadata (date/time of photo, focal of lens, exposure time, photographers comments, picture orientation, and a whole lot more). It wouldn't surprise me if the HP camera also stored an audio clip as metadata in the picture jpg.
[Ben] When you say that you've checked, do you mean that you used something like "camedia", or did you actually mount it as a storage device and looked at the files on it? The former may only show the JPG files, while the latter should show everything. My Olympus D-40, for example, produces discrete files for audio, stills, and movies.
If you're actually looking at the files on the device, then I'd have to agree with the previous post - it's stored as EXIF data.
Yes. It is definitely stored as EXIF data. Ran a jpg file into emacs and had a look. There's a nice RIFF/WAV header block right in the file. Of course, the picture files without audio don't have the header.
More reading leads me to think that some cameras use 2 files and others embed the audio into the picture. Mine is that later
So, is there a way to play the audio in the pictures on Linux?
[Lew] I'm not sure, but it's likely that the audio is stored in one of the EXIF (JFIF metadata) tags. There are tools available that can extract EXIF tag data, ranging from the digikam/gphoto2/libgphoto tools to standalone tools like jhead. Perhaps one of these tools can extract out the audio, and you can play it from there.
Yes, it helps. Problem is to find a tool to do the extraction. digikam, etc (based on gphoto2) do NOT seem to support audio play/extraction.
[Ben] 'gphoto2' supports a '--get-audio-data' option. There are probably a number of other programs; googling for "exif audio extract linux" comes up with 40,500 hits.
I think from reading and a bit of testing that --get-audio-data just copies .wav files if they are on the camera. I could be wrong, but I could not get this program to extract data.
I did the google as well I found 2 candidate programs:
dphotox - this appears to be a great program, but I can't access the
download site ftp://ftp.mostang.com/pub/dphotox I sent
David.Mosberger @acm.org a note, but no reply as of yet. This is being
distributed as a binary only ... something to do with non-disclosure
according to the web page (which is accessable
http://www.mostang.com/dphotox )
EXIFutilsLinux2.6.2.tgz is another package which works. Installed and tried it. It is shareware and they want a bit of money to unlock all the features.
Amazing, the files I did extract sounded not bad at all.
I can't imagine that getting the audio out is much more than trivial. I just don't have time right now, but I did compare the extracted file to the data in the camera file and it is identical. Just a matter of figuring an offset and the size.
[Jimmy] I shouldn't imagine it's even that difficult: the audio is stored as an EXIF tag, so you really just need to extract the contents of a specific tag. (Hint: with Perl, Image::EXIF and Data::Dumper are your friends).
If you want to send along a sample file, I'd be happy to give it a stab/eat my words
[Heather] dd has a very nice 'skip' option as well as 'count'. if your 'blocksize' is set to 1 and you are otherwise able to calculate how long to make the cut, you should be able to do something like substring extraction, on a file basis.
If our gentle readers have more ideas, or someone would like to do an article on really getting the most out of your camera under Linux, it'd be just the kind of thing to make Linux just a little more fun
I have a number of issues with tcsh (not my choice..) shell scripting I need help with.
Basically I'm writing a shell script that automates a long setup procedure. This top-level script is in bash, however the bulk of it is comprised of commands that are fed to a program which is, in essence, a tcsh shell. I've achieved this by using the << redirector. I need help on two points:
1) Is there any way of suspending input redirection, taking input from
the keyboard, and then resuming input from the tcsh script?
[Ben] There is, but it is Fraught With Large Problems. I'm not that familiar with TCSH, but I've just had to do that in Perl - essentially, I was writing a Perl version of 'more' and had to answer the question of 'how do you take user input from STDIN when the stream being paged is STDIN?' It requires duplicating the STDIN filehandle... but before you start even trying to do it, let me point you to "CSH Programming Considered Harmful" - Tom Christiansen's famous essay on Why You Shouldn't Do That. If it's not your choice, then tell the people whose choice it is that They Shouldn't Do That. The task is complex enough, and has enough touchy problems of its own, that introducing CSH into the equation is like the Roadrunner handing an anvil to the Coyote when he's already standing on shaky ground over a cliff.
To give you some useful direction, however - the answer lies in using 'stty'.
2) There comes a point towards the end of the script when two shell scripts are run simultaneously. These shell scripts open up individual xterm windows to run inside. I'm wondering, is there anyway of having the tcsh script monitor stdout of one xterm, and upon the output of a certain piece of text, echoing a command into the stdin of the other xterm?
[Ben] Why not 'tee' the output of the script - one 'branch' into the xterm and the other into a pipemill (or whatever you want to run 'grep' in)?
Any insight or knowledge on the matter would be very much appreciated. I hope I have provided sufficient details.
[Ben] You have - from my perspective, anyway.
If the gentle readers have more to say, please let Aengus know, and cc The Answer Gang so we can comment on the results or see his answer in a later issue. Artciles on working with shells beyond bash are always welcome. -- Heather
There's a mistake in my "WSGI Explorations in Python" article. http://linuxgazette.net/115/orr.html It says,
............... But both sides of WSGI must be in the same process, for the simple reason that the spec requires an open file object in the dictionary, and you can't pickle a file object and transmit it to another process. ............... |
Actually, the spec requires a file-like object, so an emulation like StringIO is allowed. StringIO is pickleable:
>>> from StringIO import StringIO >>> sio = StringIO("abc") >>> p = pickle.dumps(sio) >>> p "(iStringIO\nStringIO\np0\n(dp1\nS'softspace'\np2\nI0\nsS'buflist'..." >>> sio.read() 'abc' >>> sio.read() " # End of file. >>> sio2 = pickle.loads(p) >>> sio2.read() 'abc'
cStringIO, however, is not pickleable.
This is regarding Hugo Mills query on how to build a Debian initrd without devfs.
Now why would you be wanting to build a Debian kernel without devfs.
Surely you haven't bought all that stuff by Greg K.-H. about devfs
being bad design?
[Rick] Surely, it would be rude to speak ill of the dead. As we say in Norwegian, "Aluv ha sholem."
I assume that you are planning to use Debian's kernel-package (make-kpkg) utility to build the kernel. This you can do without worrying about anything. Just build a kernel without devfs and other options as you want them.
The initrd that is installed along with the kernel is built (providing you specified that you wanted it to be built) at the time when you install the kernel-image-x.x.x-y package.
This initrd is build by a set of tools called (what else) initrd-tools; the principal among them being "mkinitrd". Now "mkinitrd" takes a conf file /etc/mkinitrd/mkinitrd.conf so you can make some changes there.
I haven't tried this but you would need to create a script in /etc/mkinitrd/scripts that would setup the necessary device files in the $INITRDDIR/dev.
More importantly, the script /usr/share/initrd-tools/init is the "init" that is put on the initrd image. You would need to replace this with your own version as the default one makes use of devfs.
If you are keen on sorting out all these issues you should probably contact the maintainer of initrd-tools as Debian's initrd will have to give up "devfs" at some stage since Linux 2.8 won't have "devfs".
Just a thought, but how about if he compiles a plain-jane Pentium I kernel? It could be that the more recent kernels (and GCC?) might be putting in CPU instructions that didn?t get called before, or they are called more often now and are causing other errors. My experience is if the system is locked hard like he implies, then it's probably a hung CPU not answering interrupts (as he alluded to).
[Heather] Except for the part about how it answers them just fine under 2.4.x kernels, this seems plausible. It'll be tried.
He might also try limiting his use to the 768MB of RAM that his MB officially supports. Either by using the kernel command line "mem=768M" or put in only 768MB of RAM.
As a side note, he might want to run "MEMTest86+" (http://www.memtest.org/) and see if that sees any RAM errors.
There just might be a reason the MB manufacturer didn't recommend >768MB RAM.
[Heather] The full gig worked under 2.4.x kernels however some time has passed. So, this is a very worthy suggestion. Also a current 2.4.x kernel will be tried, if the hardware is failing in this sense that might be affected too. Note to readers: the good folk at MEMTEST do occasionally update their test suite. Looks like the last update was in 2004 sometime - but some of the rescue disks might have an older edition in them.
Midi plays, but it is not easy. I am running Slackware 9.1 with a 2.4.28 kernel on a K6III 400.
I am using sfxload from the awesfx-0.5.0d package to load soundfonts on to a SBLive soundcard
If you load the soundfonts and play a midi, you may have to download the soundfonts from the SBLive card prior to playing a wav file. The soundfonts do not stay loaded very long, so you have to check the available SBLive memory prior to playing a midi.
Perhaps this will help.
A tickler about last month's issue taking so long to publish... -- Heather
Any news on the when the latest Gazette is out? Or have I missed the announcement... Being subscribed on both of my accounts to the announcement list...
[Ben] I figured we'd get mail from our readers about now. The new issue should be out tonight, Martin; the problem was that - this being summer - many of our authors are on vacation, and we were a bit thin on articles. Several of the folks in The Answer Gang had, very capably, scrambled their jets and kicked in a bunch of material, and I've been working to get it all organized. Blame the delay on me.
For all our readers, if you've ever wanted to try your hand at writing - we're always looking for new authors. In the worst case, if your submission gets rejected - and this is part of my commitment to LG - you'll get a note explaining exactly why it was rejected, along with suggestions on how to improve your writing. That is, at the very least, you'll get to learn something useful - and you may well end up getting published, which is not a bad thing to have on your resume. So don't be shy, folks - read our Authors' FAQ and send'em in!
It is our preference to ship an issue somewhere around the first of the month. Our lives including work in the weekdays have led the last several issues to come out somewhere around the weekend that's nearest; with the articles that came in late, we ran a bit overtime even by that standard. Sorry. But I also encourage people with good articles that they feel need some work, to contact us and get into the sequence. You needn't always publish in the same month - we won't write your article for you, but our Articles@ staff may be able to point out some directions for improvement, and we get a new author out of the deal, too. So everyone wins -- Heather
I know that Thomas, at least, is away from the City, but - just for my own peace of mind - are all the Answer Gangsters from England OK? That would be Mike Martin and Neil Youngman that I recall; if anyone else can think of others, I'd appreciate it if you could ping them and CC the list.
[Thomas] Aww, thanks, Ben. Actually, I was only 33 miles from London at the time. I was in Stevenage, a town around London visiting my Grandparents. Would you believe they have broadband? Heh. More modern than my parents.
But I'm well, and accounted for.
And I'm very glad to hear it!
[Thomas] I just hope Neil is, although as I know Neil is around the Pin-Green area (where my grandparents are), I would surmise he too is just as well.
Yes indeed; he's emailed me (and as I recall, cc'd the Gang on it.) I haven't heard back from Mike yet, though - it's a bit worrying. Since you live in the same small island, could you perhaps walk over and knock on his door?
[Neil] Ben your concern is appreciated. I was working from home that day, fortunately miles away from all the incidents. My wife was working in London as usual, and the first bomb was on her route in. Luckily she was already at work when it went off. Although she had a very unpleasant journey home, we are lucky it was no worse than an inconvenience for us. With 49 confirmed dead and more than 25 missing, our thoughts are with their families.
[Thomas] Small? Hehehe, Ben, sail your boat round these waters, I'll show you around this place.
[Jimmy] There was a lot of off-topic chat in here too: enjoy the Launderette if you're interested
...making Linux just a little more fun! |
By Jim Dennis, Jason Creighton, Chris G, Karl-Heinz, and... (meet the Gang) ... the Editors of Linux Gazette... and You! |
We have guidelines for asking and answering questions. Linux questions only, please.
We make no guarantees about answers, but you can be anonymous on request.
See also: The Answer Gang's
Knowledge Base
and the LG
Search Engine
Hello everyone -- welcome, once again, to the world of The Answer Gang.
There's a world of people out here doing good things. As my cover art raises a cheery note to those who are part of the space programs (not just for the USA program, though certainly since that's where I live that's the pics I'm looking at) - there's those of us who not only hope for a brighter future but make it so, by our heartfelt efforts and getting our hands deep in code and craft.
As good fortune would have it, I'll get to meet a larger batch of them at this year's LinuxPicnic than last. And I can reasonably hope I'll see a decent batch of you folks at Linux World Expo in my area too.
Why is this important, you might ask. It's the Internet Age; people live on their cellphones, podcast LUG radio reports at each other, spend more time in IRC than visiting their aunts and uncles, mail order things via PayPal or other money-kindred and about a billion online stores. Who notices that real world thingy? The wattage in the Blue Room is up way too high, too. But that's just it -- it may be a big blue room... but it's the same world we all live in... and we've all got a much finer chance of doing our best if we learn to share the bright marble Nature has granted us.
Hooray for open source. Have a great Summer, folks. See you next month.
From email@example.com
Answered By: Rick Moen, Lew Pitcher, Jimmy O'Regan, Bruce Ferrell, Neil Youngman
What other choice is there besides Samba? Am I wrong for dismissing Samba due to its Microsoft taint?
(I do have to use Samba at work. So far it's been fine except I had to use the "cifs" filesystem instead of "smbfs". Apparently our server pretends to speak the older smbfs but actually doesn't.)
[Rick] Well, if you need help disposing of those troublesome spare CPU cycles, there's always SFS (http://www.fs.net).
Personally, my preferred solution is called SMTP, aka "Please drop the mail off right here where I am, thanks" -- for values of "where I am" equating to "the machine I ssh to, where mutt is left running permanently under GNU screen ".
Tridge's reported solution is to use rsync (what else?) to mirror his mbox between his SMTP host and whatever machine he's sitting at.
OK. I meant for the general problem of mounting remote filesystems, not the specific problem of remote mailboxes.
[Rick] I have nothing against you changing the focus of the discussion in that fashion; I just note that you've done so. Enjoy.
For that there's only NFS and Samba? (rsync, scp, and ftp don't count
It looks like SFS on Linux is built on top of NFS, so I'm not sure it counts as a "third" one. http://www.fs.net/sfswww/linux
The reason for my question is, there doesn't seem to be a "good" solution for sharing filesystems on Linux. For years I keep hearing:
NFS: Unreliable! Doesn't play well with file locking!
Samba: Evil! Microsoft! Proprietary protocol! Embrace and extend!
So what's the organization that wants a central fileserver to do?
[Rick] Take your pick:
- AFS, or
- It depends.
Did Microsoft in fact create something better than NFS (better = more reliable and better designed), or is it just different?
[Rick] They're different. It would take a long time to go through the differences, and I'll leave that to some other poster.
[Lew] I won't comment on "better than NFS or just different", but I will take exception to the implication that Microsoft created the protocol.
[Rick] I also recommend hearing hearing Jeremy Alison give his standard lecture, if people want to hear the full details of just how bad CIFS/SMB really is.
[Lew] I will give Microsoft credit for extending an already existing protocol, but the basics come from IBM's NETBIOS.
[Jimmy] Well, there are actually three different fileserving systems in the heap that is MS fileserving: NetBIOS, CIFS, and DCE DFS. CIFS may or may not depend on one or both of the others.
MS's file serving is much, much better for file locking (but you only get the benefits of that from software that uses MS's locking API). It's also better to use Samba in an environment where there are several Unix variants, and you care about ACLs -- the Samba team 'embraced and extended'[1] CIFS to add marshalling for the various ACL types, which NFS doesn't do. (Well, NFS4 might do, I don't know).
[1] They just like saying that, as far as I can make out. AFAICT, they just added an extension that plays well with others, and looks like any other unknown DCOM interface to clients that don't look for it -- it doesn't get drunk at the party and throw up on the other guests.
[Bruce] Umm Jimmy, aren't NetBIOS/NetBEUI simply transport protocols? I think it might be more appropriate to say SMB and DCE DFS. And DCE DFS is actually built on top of SMB, but I could be wrong there. I just set these things up. I'm too busy to look at the messages anymore. And I think you neglected NCPFS... Not that anyone does much with Novell protocols anymore.
[Jimmy] ...cue brain dump.
This may not be entirely accurate, because: it's 6am, and though I was working nights last night, I didn't sleep much during the day in the hopes of readjusting to normal hours, and this is stuff I mostly learned back in the days of NT4, when I was in college, and went a bit further than strictly necessary in my studies for the MCSE exams I was never able to afford to take, though fortified with some investigations last year when Mike was asking about smbfs vs cifs. The article I wrote about outliners came the month after that, and AFAIR I included an example outliner file that contained some specifics, such as RFC numbers etc.
- NetBIOS is an API (originally, IIRC, a set of DOS interrupts)
- SMB is the part most people think of when they think of NetBIOS, but it actually uses a transport protocol such as NBT (NetBIOS over TCP/IP), NetBEUI, or NetBIOS over SPX.
- SMB, NetBIOS, and possibly NBT were created by IBM
- Microsoft extended these, originally while working with IBM on OS/2 for LanManager (y'know, the easily crackable password hashes that made NT's network authentication so horribly insecure)
- CIFS is a version of SMB that doesn't require NBT -- that's why smbfs and cifs are separate kernel modules -- that also includes extensions for NTFS's features such as multiple file streams[1]
- DCE DFS is something like NFS, over DCE RPC instead of Sun RPC
- Microsoft uses an extended version of DCE RPC, Object RPC, as the basis for DCOM. COM interfaces are implemented locally using C++ vtables, which are marshalled over ORPC, which in turn is passed over NT's (network) Named Pipes: (extended) DCE RPC over SMB/CIFS.
I didn't mention ncpfs because I was answering the second question (NFS vs. Samba), not the first (any network file system).
[1] This is one of the places where NT shows its VMS heritage, as all file streams are preceded by ::$, such as ::$DATA, where the data is contained. (If that seems familiar, it may be because of the IIS flaw where it would send you the unprocessed source of ASP files if you appended ::$DATA to the file name).
And now IBM has dumped OS/2 and encouraged users to migrate to Linux. http://www-306.ibm.com/software/os/warp/migration.html http://slashdot.org/article.pl?sid=05/07/15/0245221&tid=136&tid=190
(Scratches head.) There are still OS/2 users out there? And they are more technical than Windows or Mac users who are scared of Linux?
[Neil] Heck, there are still VMS users out there, there are probably still RSX users out there. Generally these are people who have specific requirements, e.g. real time, stability, security, that have had the sense not to jump on the Windows bandwagon, because it doesn't meet their requirements.
So yes, I reckon OS/2 users are generally more technical than "Mac and Windows users who are scared of linux". They may migrate to Linux, but they will do it when they are convinced it meets their requirements better than the alternatives and when it suits them, not a minute before.
[Lew] You bet. OS/2 is/was heavily used in the banking industry as 'Teller' terminal systems and as operator control systems/interface systems to IBM mainframes.
My employer (a Canadian bank) has a multi-year project currently running to migrate our approx 15,000 OS/2 branch workstations and branch servers to another OS. Linux was considered, but in the end, my employer went with WinXP.
Our OS/2 users are no more technical than the cashier in your local grocery store. Our OS/2 applications are quite sophisticated.
From Mark Jacobs
Answered By: Ben Okopnik, Jimmy O'Regan
I manage a web server that is used by an internal help desk, currently this help desk uses telnet to access aix servers on our corporate wan. I have multiple pages that serve URL's to the aix machines e.g. telnet://hostname <telnet://hostname/> . We are in the process of changing all of these servers to use SSH and need to know how to make ssh://hostname a registered protocol so that I can convert my links and have them work. I am unable to find any information on where/how you set up a protocol and associate it with an application. Is this a system or browser issue? Any information you might have or be able to point me to would be a big help.
[Ben] In the future, please send your questions in plain text; that's the accepted format for The Answer Gang. The instructions for setting your mail client to do this, as well as much other relevant information, can be found in the "Asking Questions of The Answer Gang" FAQ at http://linuxgazette.net/tag/ask-the-gang.html
Regarding your question, there's no "registration" that you can do to make SSH magically happen from the server side: URLs are parsed on the client end, by the specific browser that's being used.
Note that some browsers - e.g., Konqueror - do parse 'ssh://' URIs; they fire up a console with a login prompt (which is, of course, the correct response - SSH is a secure SHELL protocol.) Konqueror also supports the 'fish://' protocol - an SSH-based connection that allows file viewing and could be a bit closer to what you want... or maybe not.
The problem is that most other browsers do not support these schemes - and many cannot even be adapted to do so. There's a huge number of browsers operating on a number of OSes, and unless your company has some sort of a draconian software policy, you have no way to restrict them or control which ones people use.
The obvious solution here, in my opinion, is to run a web server, and place your documents on it. Telnet should go away - sending passwords across the network in plain text and IP-based authentication are not sensible things to do in today's world. Running a web server, particularly a simple, read-only one like "thttpd", is a trivial task requiring either no or only a few seconds of configuration, and the replacement of telnet by SSH and HTTP should significantly decrease your vulnerability profile.
[Jimmy] For Mozilla, you can add protocol support using Javascript: the URN support XPI (http://piro.sakura.ne.jp/xul/_urnsupport.html.en) is a good example. (The URL specific code can be found here: http://piro.sakura.ne.jp/xul/codes/urnsupport/content/urnsupport/URNRedirectService.js)
For Konqueror, you add protocol support by writing a KIOSlave. There's a tutorial here: http://www.heise.de/ct/english/01/05/242
For Dillo, you write a DPI: http://www.dillo.org/dpi1.html
If for whatever reason you need to run Internet Explorer using Wine, you can add protocol support by following the example of this mail (http://www.winehq.org/hypermail/wine-patches/2005/06/0776.html - a patch to add support for MS's res: protocol to Wine), and this mail (http://www.winehq.org/hypermail/wine-patches/2005/07/0049.html - registers the protocols). This is Linux/Wine specific though
From Benjamin A. Okopnik
Wow. I've got to say that I'm just stunned by the moronic thing that Mutt just did. It's probably the stupidest thing I've ever seen from any Linux app - it rivals 0utlook and IE for complete slack-jawed idiocy.
Once in a while, I get false positives in my spambox. Today, I got one from somebody posting to TAG (I don't recall the name - somebody who had sent it to the wrong address and then bounced the DSN + original mail to TAG), so I saved it to my main mailbox by hitting 'v' (view), selecting the "pre-Spamassassin message", hitting 's' (save), and choosing "/var/mail/ben". When I opened the message, I decided to repeat the operation (i.e., get rid of the "wrapper" message) - so I again hit 'v', selected the original message, and hit 's'. Mutt then popped up a message that said something like "file exists - are you sure?" - and since I had done the same operation dozens of times before, I hit 'y' for 'yes'... at which point, my mailbox got wiped. Zeroed. Nothing left of the 20 or so messages I was going to answer, not even the message that I had theoretically saved. (Mike, your Python article was part of that - so if you could resend, I'd appreciate it.)
I'm in a bit of shock here, and rather pissed off. In all the years I've used Mutt, I never realized that this essentially random bomb was hidden in it - and triggered off by a message that seemed to make sense in the context.
Dammit. Double dammit, since I use my mbox as a sort of a backup "to do" list - I leave emails that call for some kind of action in it until I've completed that action. Grrrrr.
[Kapil] Commiserations for your loss.
Thanks. As best as I can recall, there was nothing really critical or earth-shakingly important in there, but important enough for the loss to create a high annoyance factor. Semi-amusingly, two of the messages got "saved" by my despamming mechanism: they had been sent to me by a reader who dressed them in spam-like clothing (all-HTML content, funky mail hosts, etc.), and when I forwarded them to TAG - they were in regard to Heather's query in the Mailbag - they got spam-slammed again. So, between a little info message that Kat sent me, Mike's article, and the two not-spams, I've got four messages back.
[Kapil] You could try ext2 recover mechanisms. They might work.
I hadn't thought of that at the time, and given that the same file had new mail in it just a few seconds later, and a very large email in it yesterday evening, I'm pretty sure that there's nothing left.
[Kapil] At one time I had a similar ToDo list at the top of my mbox and my mailer (vm/emacs) of the time did something similar to what mutt just did to you. I was able to recover my ToDo list (though not the more recent stuff in my mbox).
Partly as a result of the above catastrophe, I moved away from vm/emacs but (I think) more importantly, moved away from the mbox format. I am currently an advocate of the MH or maildir formats for personal folders. One mail---one file. Almost no screw-ups by a mail user agent can screw up all my mail again.
[Heather] Unless it screws up the directory. Also mdir index mechanisms can get mangled; though it seems to take more work, it's much wonkier when it does.
I've thought about that in the past. My hindbrain had made some disquieting noises about not being able to search the archive quite as effectively - which does not appear to stand up to rational analysis when considered soberly - and so I'd left it alone.
Hmm, perhaps this is becoming a Gang-relevant question. Folks, what do you think of the pros and the cons of MH vs. Mbox? The net provides much in a way of "yea" and "nay" answers, with only esoterica for support (speed of opening 2,000 messages - wow, very important criterion to me...), and I'd like to hear if anyone has had other positive or negative experiences with either format.
[Rick] (Note: I've studied the pros and cons of Maildir a bit; MH much less so. To a first approximation, I'll assume they're similar.)
1. People with their mailboxes on Nightmare File System need to migrate to Maildir or MH format with all reasonable speed, because of the greatly increased chance of lossage.
Despite Sun's love affair with NFS and their subsequent attempts to smear it on sandwiches, mix it into house paint as a mold retardant, and use it for greasing subway trains, I avoid it like the plague.
[Rick] 2. Otherwise, the advantages of Maildir/MH format strike me as somewhat but certainly not overwhelmingly compelling. I vaguely recall that the mutt MUA has an (optional) indexing feature that reduces the performance hit of Maildir. People who've migrated to that seem happy with it.
I still keep absolutely everything in mbox files, anyway, because I'm lazy and set in my ways, because I've not yet been bitten by a glitch the way you were, and because something about huge trees of little files just doesn't seem right.
We seem to share a similar set of prejudices, Rick. "Lazy, set in my ways, trees of little files vaguely wrong" - yep, that's me to a tee. So far, I haven't heard any compelling arguments for switching - I was hoping that somebody had one...
[Kapil] Having already called myself an advocate for MH/maildir let me point out one disadvantage of MH/maildir on a multi-user system where you do not have control over disk quotas. Both MH/maildir could cause you to run over file (not space) quota. This could also be a problem over NFS (too many NFS file handles ... ).
Y'know, I really enjoy this kind of thing. When I ask this kind of questions, people's answers tend to trigger off the "oh, yeah... I remember reading/hearing/seeing that!" 8 times out of 10. It calls up a strong echo of Brunner's "Shockwave Rider": "We should not be crippled by the knowledge that no one of us can know what all of us together know."
Thanks for the reminder, Kapil!
[Kapil] I have not noticed speed issues. I know "mutt" is a four-letter word in Ben's book right now, but it can employ "header caching" so that MH/maildir folders can be scanned quickly. This also mitigates the NFS problem somewhat. Other mailers may do the same.
Mutt did this one stupid thing in all the time that I've used it - under a defined set of circumstances. I now know enough to avoid those exact circumstances; the only thing that's left is a question of "do I trust Mutt not to present me with other equally boneheaded non-choices?" Well... there are no guarantees, but I believe that Mutt was written with the best of intentions (as well as being subject to the Open Source debugging mechanism), so, yeah, I'm willing to trust it. Conditionally.
[Kapil] Between MH/maildir, the former should be avoided if there is some possibility that the folder could be accessed by two programs at the same time.
To Ben's question I would add the following compatability related question. "Do most mail-related utilities handle MH/maildir nowadays?"
[Nod] I'm very much a CLI user by preference. Looking at the list of Maildir clients, it seems that most of them are GUIs - which mitigates against my adopting it. Although there certainly are CLI clients, they - other than Mutt - are not very common. Given that I log into a variety of systems to read my mail, often over low-bandwidth links, this definitely reduces my options.
[Rick] (Again, I don't know much about MH-format support.)
I have information on various Linux MDAs (mail delivery agents) and LDAs (local delivery agents), here, including which mail-store formats they support, where known:
"MDAs" on http://linuxmafia.com/kb/Mail
I have similar information on 123 MUAs (mail user agents = mail clients) known to be available for Linux, here:
"MUAs" on http://linuxmafia.com/kb/Mail
[Sluggo] Actually, speed of opening mailboxes is important to me. I switched from mbox to MH format years ago because it's "safer" and more "ideologically correct" (notwithstanding Rick's comment to the contrary; I just prefer not stuffing multiple things into one file with a program-specific "separator".) But then I switched back so I could get the "You have new mail" messages from zsh.
I think that this has been one of my dimly-sensed, not-fully-formed objections to Maildir/MH - a feeling that it's not quite as well supported/debugged as mbox. I don't have much of a problem with the idea of a defined separator in the file; the only time I've seen it screw up was when my mail server went bonkers and delivered me a box of messages where the 1st message was headless (the clue came when I looked at one of the old emails in the box - the original content had been extended by something totally unrelated!)
[Sluggo] That seems to work only with file mailboxes, not directory mailboxes. I was concerned about losing mail, then thought, "How often has mbox ever trashed my messages anyway?" I can't think of a single instance where new messages stomped on existing messages. Mutt does do sometimes display an mbox message as two messages, split arbitrarily in the middle, with empty headers for the second (and thus a date like Jan 1980), but that was never critical. NB. I don't use NFS, especially not for mail spool directories.
It sounds to me like an upstream mail server that fails to use the "From hack". The last time I recall that happening was in an email from a listserv server - about ten years ago.
[Sluggo] But with my current computer I keep my mail on my ISP's mailserver and use IMAP. I'm less concerned about ISP snooping or the mailserver going down than about my own computer going down after it has downloaded mail, or my Internet connection randomly freezing for several hours when I was away from home and had to look up a phone number in an email. But I found mutt's IMAP user interface sucks ass: you can't set an IMAP address as your primary inbox, apparently, meaning you have to type this verbose syntax to access it each time you start mutt. I looked at other mail clients. Kmail kept showing a long-outdated configuration I couldn't override so that alarmed me. I settled on Thunderbird, although it sometimes gets its index pointers out of alignment and won't let me access a new message, so I have to restart it. Someday I'll look over the other clients available. I definitely want a client that can read mail in place in standard formats, rather than one that wants to slurp it up into its own format (and deny access to other mail programs). I think both Thunderbird and Kmail want to slurp up local mailboxes.
[Kapil] This has to be an old version of "mutt". The newer one seems to allow
set spoolfile = imaps://luser@ghost/INBOX
Of course, "mutt" is not particularly good with IMAP. So my current config is based on "offlineimap" which copies all the mail from the server into a local maildir. It also syncs whatever changes I make to the folder back onto the server; in this it improves on "fetchmail" which is one-way.
Of course, this setup means one uses more bandwidth than is strictly necessary just to read those mails that one is interested in. I have so far not suffered any glitches in this setup (but I'm waiting ...).
[Heather] My positive experiences with mdir are about arrival speed on a heavily loaded server. Also, among the IMAP implementations, Courier was about 10x or 11x as fast as wu-imap, which was fragile, and Cyrus was only about 3x. Courier backends with maildirs, though I'm not sure that's where all of its benefit comes from.
The notes and specs rant about mdir being safer but a lock is a lock. They're probably right since I have seen mbox files get bad hiccups from intermingling messages when locks fail. On the other hand individual mails in mdir use up whatever storage unit is going around. Maybe on reiser (where tails that are tiny are often crammed into one stroage unit) this is less of a pain.
> I know that this is a bit like asking you to lock the stable door > after the horse has bolted it, so commiserations once again. ^^
[ puzzled ] If the horse has already bolted it - very smart horse, that - why would I bother locking it? Or is this a multiple-level security implementation?
[Kapil] Thanks to one V. Balaji (Tall-balaji) for this excellent improvement of a classical proverb. I have used this version ever since I learnt it from him.
[Heather] Not only that but after pulling this prank, the horse ran away really fast
From Riza Aziz
Answered By: Jimmy O'Regan, Ben Okopnik
Dear Answer Gang,
I am having some problems with reading converted UTF8-encoded web pages on my Palm PDA. I can't figure out how to transcode UTF, which the Palm doesn't understand, into ISO8859-1, which the Palm displays properly.
Some background: I have a script that downloads the latest news from a few sites. It's an ugly RSS look-a-like for sites that don't support RSS. I then use "htmlconv", a Perl script from the txt2pdbdoc package, to convert the downloaded pages into a text-only format which I can then upload to the Palm. The script also converts character entity references (egrave, quot etc.) into ISO8859-1 characters. On the Palm, I use Cspotrun to read the PDB files.
I downloaded the txt2pdbdoc package a long time ago and it worked fine with Redhat 6. When I upgraded to Redhat 9, Perl's UTF handling broke the script because it assumed I wanted the converted web page in UTF. This poses a problem because the Palm doesn't understand UTF characters; accented letters and certain punctuation marks become strange symbols. By adding
use encoding 'latin1'; use open ':encoding(iso-8859-1)';
everything worked again.
Now, I've come across a website (http://www.zmag.org/recent_featured__links.cfm) that uses UTF directly. Instead of using "egrave" for an accented E, it uses the UTF character directly. The converter script doesn't know what to do with the character and I get all sorts of strange symbols when viewing the file on my Palm.
Is there any way to convert the UTF characters directly into ISO8859-1? And how do I get rid of any characters that don't map directly, so strange symbols don't show up on my Palm? I've messed around with the encoding pragmas but I can't get anything to work.
[Jimmy] Righto. I have a silly perl script that prints out the Polish alphabet (so I don't have to trawl through the iso-8859-2 man page for the long names of the odd characters) that looks like this:
See attached alfabet.pl.txt
To get iso8859-1 output, I could replace the last two lines with:
use Encode; $alfa = encode ("iso-8859-1", $Alfabet); print "$alfa\n"; print lc "$alfa\n";
(or perl alfabet.pl|recode 'utf-8..iso-8859-1')
To get rid of the extra characters, you'd probably be better off converting to ASCII rather than ISO-8859-1 -- Perl will print a question mark instead. (recode will too, if you use the -f option, to force an irreversable change. Otherwise, it'll stop as soon as it finds a character that it can't convert).
I looked everywhere in my system and I can't find recode. Does it belong to any particular package?
[Jimmy] It's normally in its own package. http://packages.debian.org/stable/text/recode
I did try substituting all the UTF characters with their common ASCII equivalents e.g. open & closing quotes with ". I created a hash as above and used s/// but nothing happened.
One strange thing: the single closing quote character under UTF is \x{2019}, which I tried substituting for. However, running hexdump on the file shows the character is actually E28099... what gives? What can I do to get a straight ASCII dump of the file?
[Jimmy] From http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
............... The following byte sequences are used to represent a character. The sequence to be used depends on the Unicode number of the character: U-00000000 - U-0000007F: 0xxxxxxx U-00000080 - U-000007FF: 110xxxxx 10xxxxxx U-00000800 - U-0000FFFF: 1110xxxx 10xxxxxx 10xxxxxx U-00010000 - U-001FFFFF: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx U-00200000 - U-03FFFFFF: 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx U-04000000 - U-7FFFFFFF: 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx The xxx bit positions are filled with the bits of the character code number in binary representation. The rightmost x bit is the least-significant bit. Only the shortest possible multibyte sequence which can represent the code number of the character can be used. Note that in multibyte sequences, the number of leading 1 bits in the first byte is identical to the number of bytes in the entire sequence. Examples: The Unicode character U+00A9 = 1010 1001 (copyright sign) is encoded in UTF-8 as and character U+2260 = 0010 0010 0110 0000 (not equal to) is encoded as: ............... |
If you want to look at the raw text, just use a text editor that isn't unicode aware.
[Jimmy] One thing to be aware of when dealing with files created on Windows (as the page you pointed to was) is that Windows usually uses UTF-16LE rather than UTF-8.
Yeah, created with MS Frontpage. Blech All this time I thought that ISO8859-1 was the standard encoding for web pages, with other encodings used for Chinese, Japanese script etc. Is mixing and matching allowed?
[Jimmy] I don't know, to be honest. I'd assume that if you want to do that, you'd be strongly encouraged to use Unicode. (Umm... actually, these days, you're encouraged to use XHTML rather than HTML. Since XHTML is based on XML, it's UTF-8 unless stated otherwise).
Thanks for the link to an excellent website on most things Unicode. It cleared my misconception that Unicode sequences correspond to actual byte sequences, when they don't e.g. \x{2019} is actually E28099, not 2019.
[Jimmy] Erm... be careful with your phrasing there. The part that's written to disk is an encoded version of the Unicode sequence. UTF-7 is a good example of how it works: IIRC, it's UTF-8 encoded with Base64.
I think I have the problem mostly solved. I added the following pragmas:
use encoding 'utf8'; open( OUTPUT, '>:encoding(iso-8859-1)', "$txt_file" )
So, the script processes everything in Unicode but spits out the results in ISO-8859-1.
The hard bit for me is the substitution. The following snippet is supposed to do the substitution, but it doesn't work:
%utf_entity = ( "\x{2019}", '"', "\x{201c}", '"', "\x{201d}", '"', ); s/(\X+);/exists $utf_entity{$1} ? $utf_entity{$1} : $1 /eg;
Instead, I get an error for each non-matching Unicode character:
"\x{2019}" does not map to iso-8859-1 at /home/riza/bin/htmlconv-utf line 302
However, using s/\x{2019}/"'"/eg, s/\x{201c}/"'"/eg and so on for every non-matching character works. It's a really clunky way of doing things but the resulting file displays perfectly on the Palm. How do I match hex sequences for non-matching Unicode characters in a regex, without wiping out all other characters?
[Jimmy] OK, so you have something like this:
See attached utf-1.pl.txt
With some functions from the Encode module, you get the right output:
See attached utf-2.pl.txt
The regex still isn't working though. Let's break it down:
I'll assume the semi-colon was a typo. I think the pattern should really be (\X) though; you're using it to match individual characters against a hash, so you don't want to get more than one character. If you want to see what you're matching, you could use something like this:
s/(\X)(?{print "Matched: $^N\n"})/
and shouldn't it be $utf_entity{"$1"} instead of $utf_entity{$1} ?
But do you really need to do that stuff with the hash when you could use tr instead?
tr [\x{2019}\x{201c}\x{201d}] ["];
Jimmy O'Regan wrote: > and shouldn't it be $utf_entity{"$1"} instead of $utf_entity{$1} ?
OK, no. Here's a working version:
See attached utf-3.pl.txt
I think the problem was with the encoding of the file handle and a bit with the regex itself. Below are snippets of my version of the converter script. However, I'm following the original author's method of slurping up all the input and putting it into $_, whereas your script loops through the input. Which method is better?
[Jimmy] How long is a piece of string? (No, really - if you know your file will fit into memory, your way is better, otherwise my way is better (I think ).
[Ben] That being the big caveat - although HTML files are not likely to be so huge that they'd cause an OOM on a modern machine.
open( INPUT, '<:encoding(utf8)', "$html_file" ) or die "$me: can not open $html_file for input\n"; $_ = join( ", <INPUT> ); # slurp up all of HTML
[Ben] This is not a good idea. You're reading in <INPUT> as a list (which takes ~5x the memory for the amount of data), then "join"ing the list - seems rather wasteful, particularly since you don't need to do any of the above (entities are not going to be broken across lines.) For future reference, try this:
open Fh, "foo" or die "foo: $!\n"; { local $/; # Undef the EOL character $in = <Fh>; # Slurp the content in scalar context } close Fh;
close( INPUT ); if ( $txt_file ) { open( OUTPUT, '>:encoding(iso-8859-1)', "$txt_file" ) or die "$me: can not open $txt_file for output\n"; select OUTPUT; } ### various HTML-stripping bits here %utf_entity = ( "\x{2019}", "'", "\x{201c}", '"', "\x{201d}", '"', "\x{2026}", "...", "\x{fffd}", "", ); s/(\X)/ exists $utf_entity{$1} ? $utf_entity{$1} : $1 /eg; print "$_\n";
The above regex works. I found that I didn't have to use $_ = encode_utf8($_) to get it running, as long as the non-matching UTF characters were stripped out before output. If a character was left in, its Unicode sequence in plain text was shown in the output file e.g. \x{fffd}.
[Jimmy] It dawned on me this morning that I only needed to use the open() stuff or the Encode stuff, but I'll just stare at the ground, shuffle my feet, and mutter something about being doubly sure That stuff was a hangover from pasting a line in the wrong place, before I noticed you were trying to match too much.
[Ben] As to the script itself, well -
See attached utf2iso-8859-1.pl.txt
Use redirection to write your output to a file - or pipe it into something else for further processing.
I think your way (of looping through the file) is actually better for a large range of file sizes.
I usually "cat" a bunch of HTML files together before converting them with the script. Using the slurp method, a cobbled-together file of 1 mb or more pretty much kills the computer It just sits there, not processing but taking up a lot of memory. After 10 minutes I have to kill the process.
OTOH if you loop over the file, that would allow it to better allocate memory, I guess?
[Ben] Depends on your meaning of "loop over" - if you load the entire file into memory and loop over it (as both slurping and the 'for' loop will), then no. This is one of the things I constantly emphasize to my Perl students: you can easily bring down your machine by slurping files - do not do it unless you're very confident that the maximum file size will be no more than a tiny fraction of the memory.
# Wrong ways for arbitrary file sizes, OK for small files: ### Slurp into array @file = <Foo>; ### Load <Foo> into memory as an array for $line ( <Foo> ){ do_stuff( $line ); } ### Load Foo into memory as a string { local $/; $file = <Foo>; } # Right ways when in doubt: ### Read the filehandle one line at a time while ( $line = <Foo> ){ do_stuff( $line ); } ### Read a paragraph at a time, in case there are continuation lines ### (e.g., mail headers) { local $/ = "\n\n"; while ( $line = <Foo> ){ do_stuff( $line ); }
Many thanks for the help! I'm attaching the whole script, in case someone might have use for it.
See attached htmlconv-utf.pl.txt
[Ben] Both Jimmy and I mentioned the reasons why slurping can be dangerous, but there are times when you can't avoid it - although constructs like this one tend to handle most of the "line-continuation" scenarios:
while ( $line = <Fh> ){ while ( test_for_incomplete_line( $line ) ){ $line .= <Fh>; } # Process $line further ... }
In other words, if there's some metric you can use for distinguishing an incomplete line, then you don't need to slurp. Conversely, if you're looking at formatted text, you can also avoid slurping by processing a paragraph at a time:
$File = "/foo/bar/gribble.qux"; open File or die "$File: $!\n"; { local $/ = "\n\n"; # Define EOL while ( <File> ){ process_content(); } }
Asking which method is "better" makes no sense until you consider the data that you're processing. In your case, since entities don't break across lines, slurping is unnecessary - so processing it a line at a time is quite sensible.
Thanks! I guess the script's original author wrote it only to convert small, single HTML files instead of huge HTML lumps of multiple files.
[Ben] That would be my guess. Either that, or he didn't even consider the issue. Either way, handling the problem in the script would have been trivial:
# After processing all the command-line options, loop over files for ( @ARGV ){ if ( -s > $MAX_SIZE ){ warn "File $_ rejected: TOO LARGE!\n"; next; } process_files( $_ ); }
Just curious, what kind of data would have entities spread across multiple lines ie. binary data? Even plain text would be terminated with CR or CR/LF, correct?
[Ben] Well, what makes them entities is that they're atomic - i.e., irreducible units. That means that they _can't_ be broken, across lines or in any other way - otherwise they become, erm. non-entities.
[Jimmy] Erm... not quite. Let me veer off-topic a little...
In SGML and XML you can define your own entities, which can contain pretty much anything you want -- a multi-line disclaimer, for instance. Since the trend in browsers has moved towards generic XML browsers that render using CSS or XSL stylesheets (but with a fallback mode to handle the mangled mess that is HTML), defining your own entities is possible, though not advisable.
You can define binary data as an entity, but anything other than plain text will at best be ignored, at worst cause an error. If you want to output a CR, for example, you would have to use XSL-FO (though there is a way to preserve whitespace from XSL, including CR or CR/LF, you just can't do it as flexibly as plain text).
(Defining your own tags is OK, though - browsers ignore tags they don't understand. Most HTML browsers can handle XHTML[1] because of this).
[1] That is, as long as the XHTML namespace isn't prefixed, and some browsers have trouble with <br/>, <hr/>, etc. (Though they can manage <br />, etc)
[Ben] Jimmy, correct me if I'm wrong but - we were speaking of HTML character entities, right? Otherwise, the methane-based entities from the Dravidian cluster are going to complain about discrimination. If we're going to bring in every other kind of entity and ignore them, it'll look like solid grounds for a lawsuit.
To restate my point with a bit more precision, though: HTML character entities cannot be broken - otherwise, they'll be, well, - broken.
[Jimmy] Sorry. Thought the original question was something completely different.
Thanks for all the help in solving this UTF problem and giving me some insights into the murky world of Unicode, at the same time cleaning up my atrocious Perl You're all a real blessing for the Linux community. Keep up the excellent work!
[Ben] You're certainly welcome; glad we could help!
Contents: |
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The European Union directive on the patentability of computer-implemented inventions has been rejected by the European Parliament by a large margin; the final tally was 648 votes to 14, with 18 abstentions. This high turnout came following intense lobbying on all sides in the run up to the vote. As reported by The Register, the directive seemed to hemorrhage support as the vote approached. The Pro-patent camp became afraid that the anti-software patent amendments might be reintroduced and given a second stamp of democratic approval (the Commission could still shelve the whole thing, but that could be politically difficult). Meanwhile, the anti-patent activists have been keen to kill this directive, which they see as having been severely tainted by the involvement of big (huge!) business pro-patent interests.
In the aftermath of this decision, both sides have tried to claim success. The Commission, which had been pushing hard for software-patentability, portrayed the vote as offering support for the current status quo, where software patents are being tacitly allowed by the EPO. However, the possibility of better enforcement of current patent regulations regarding software-patentability has been pointed to by a UK court decision to reject a software patent on the basis of Article 52 of the EPC (European Patent Convention).
The recent behaviour of Cisco regarding the publication if a flaw in its products has highlighted the ways in which legal proceedings can be used to the detriment of individuals and indeed the security of a community. This story centres on the decision of Michael Lynn, an employee of Internet Security Systems, to publicly announce a flaw in Cisco's IOS (Internet Operating System) software. Lynn came to his decision to go public after Cisco was notified of the vulnerability, but had failed to remedy the fundamental problem. As Lynn has noted, the source-code to Cisco's IOS has been stolen twice, so he felt there was a significant chance that outside parties would soon be able to develop a practical exploit unless measures were taken to force Cisco to patch the flaw.
When Cisco became aware of Lynn's decision to speak at the Black Hat Conference, pressure was put on ISS, Lynn's employers, to prevent him from going through with his presentation. Lynn was also personally threatened with legal action. Following this pressure, Lynn resigned from his position at ISS, but went ahead with his presentation.
The basis for Cisco's legal attack on Lynn was that he had illegally obtained his information, as to do his research he had violated the Cisco license agreement with regards to reverse engineering. Although in the immediate aftermath of Lynn's presentation he was still being threatened with legal action, a settlement has since been reached. The terms of this include preventing Lynn from further using the Cisco code in his possession for reverse engineering or security research, and he is also forbidden from presenting his research on this flaw again. In the meantime, Michael Lynn is looking for a new job.
Bruce Schneier has posted (and updated) a very good summary and analysis of this case on his blog.
Preliminary work is underway to launch an EFF-like organisation for Britain
Joel Spolsky has reviewed Eric Raymond's book, The Art of Unix Programming. Incidentally, the entire book is available online.
Five addictive open-source games
Linux & Scaling: the Essentials
OpenOffice.org, FOSS, and the preservation of Gaelic
MythTV: Easy personal video recording with Linux
Another country pushes towards Linux. The Norwegian Minister for Modernisation Morton Andreas Meyer is asking governmental institutions to prepare, before the end of 2006, plans for the use of open-source. In particular, it is hoped to avoid the use of proprietary formats for communication with citizens. (courtesy Howard Dyckoff).
It has been reported that embedded Linux powered 14 percent of smart phones shipped worldwide in Q1. Meanwhile, Windows Mobile shipments made up just 4.5 percent of the market (courtesy Howard Dyckoff).
Asterisk@Home is a GNU/Linux distribution aimed at lowering the level of technical skills required for home users to be able to make use of Asterix, the open source PBX (Private Branch Exchange) telephony software. NewsForge has a detailed article on this distribution.
The Debian project has moved to reassure users by confirming that the security infrastructure for the new current release, Debian GNU/Linux 3.1 (alias sarge) and the former release (3.0, alias woody), both enjoy the benefits of a working and effective security infrastructure. This reassurance followed a brief period after the release of Sarge, during which issues with the security infrastructure prevented the issuing of updated to vulnerable packages.
From Debian Weekly News, Following the recent release of a new Debian GNU/Linux stable version, readers may be interested to peruse an online screenshot tour.
Progeny, and a handful of other Debian GNU/Linux distributors are planning to form a shared Debian GNU/Linux distribution for enterprise applications. Ian Murdock (the "Ian" in debIAN, and Progeny head honcho) has commented on this development, and it was also discussed on the LQ Radio Show.
The Debian project has announced that this year's Debian Conference was a great success with more than 300 people attending and over 20 sponsors. One highlight was the presentation about the large-scale deployment of 80,000 Debian workstations in Extramadura, Spain. The presentations were captured by the video team and are available online.
Foresight Linux, is a GNU/Linux distribution showcasing some of the newest developments in Gnome (e.g. beagle, f-spot, howl, and hal). Mad Penguin has taken a look at this distribution.
Though it is not of course based on Linux, many GNU/Linux enthusiasts will doubtless be interested to learn of the existence of FreeSBIE, a FreeBSD based liveCD. This software has been featured on NewsForge.
The Knoppix bootable GNU/Linux liveCD is now also available as a version 4.0 DVD including a huge selection of software. Kyle Rankin has reviewed this Knoppix version for O'Reilly's linuxdevcenter.com.
Coinciding with the release of version 0.1 of the Debian based Enlightenment liveCD project, NewsForge has plugged a screenshot tour of the distribution.
Puppy Linux has been profiled in NewsForge's My Workstation OS series.
SoftIntegration, Inc. has announced the availability of Ch 5.0 and Embedded Ch 5.0 for Linux on PowerPC Architecture. Supported platforms include iSeries, pSeries, OpenPower, JS20 Power based Blades and zSeries from IBM as well as computers from Apple Computer. Ch is an embeddable C/C++ interpreter for cross-platform scripting, 2D/3D plotting, numerical computing, shell programming and embedded scripting. The release of Ch and its toolkits for Linux PPC continues SoftIntegration's involvement in cross-platform scripting, numerical computing and embedded scripting. Ch Control System Toolkit, Ch Mechanism Toolkit, Ch CGI Toolkit and C++ Graphical Library are available in Linux PPC as well.
The Apache Software Foundation and The Apache HTTP Server Project have announced the release of version 2.1.6-alpha of the Apache HTTP Server ("Apache"). The 2.1.6-alpha release addresses a security vulnerability present in all previous 2.x versions (but not present in Apache 1.3.x). Apache HTTP Server 2.1.6-alpha is available for download.
Sun has announced that it will open source the next release of its Java Application Server. Also planned is to release its Instant Messaging code as open source. This will take place under the CDDL license, also used for Sun's OpenSolaris project. (Courtesy of Howard Dyckoff)
Mick is LG's News Bytes Editor.
Originally hailing from Ireland, Michael is currently living in Baden,
Switzerland. There he works with ABB Corporate Research as a
Marie-Curie fellow, developing software for the simulation and design
of electrical power-systems equipment.
Before this, Michael worked as a lecturer in the Department of
Mechanical Engineering, University College Dublin; the same
institution that awarded him his PhD. The topic of this PhD research
was the use of Lamb waves in nondestructive testing. GNU/Linux has
been very useful in his past work, and Michael has a strong interest
in applying free software solutions to other problems in engineering.
By Anonymous
This article is a follow-up to Maxin B. John's article, which introduced us to the Festival text-to-speech synthesizer and some possible applications. Here, we will push it a bit further and see how we can convert ebooks from the most common formats like HTML, CHM, PS and PDF into audiobooks ready to send to your portable player.
With the high availability of cheap and small portable MP3 players these days, it has become very convenient to listen to books and articles just anywhere when you would not necessarily have the time to read them. Audiobooks usually require very small bit-rates, and hence very small sizes - and as a consequence they are the most suitable content for the cheap/small capacity MP3 players (128 MB or less).
There are lots of websites out there catering for audiobooks needs with a wide range of choices. However, it might happen that you really want to read that article or book that you found on the web as a PDF or as HTML, and there is probably no audio version of it available (yet). I will provide you with some scripts that will enable you to convert all your favorite texts into compressed audio files ready to upload and enjoy on your portable player. Here we go!
Most of these tools are packaged in the main Linux distributions. Once you have all of the above installed, we can start the fun. We will begin with one of the most common format for ebooks: Adobe PDF.
#!/bin/sh - chunks=200 if [ "$#" == 0 ]; then echo "Usage: $0 [-a author] [-t title] [-l lines] <ps or pdf file>" exit 1 fi while getopts "a:t:l:" option do case "$option" in a)author="$OPTARG";; t)title="$OPTARG";; l)chunks="$OPTARG";; esac done shift $((OPTIND-1)) ps2ascii $@ | split -l $chunks - tmpsplit count=1 for i in `ls tmpsplit*` do text2wave $i | lame --ta "${author:-psmp3}" --tt "$count ${title:-psmp3}" \ --tl "${title:-psmp3}" --tn "$count" --tg Speech --preset mw-us \ - abook${count}.mp3 count=`expr $count + 1` done rm tmpsplit*
First 'ps2ascii' converts the PDF file or Postscript file to simple
text. That text is then split into chunks of $chunks lines; you
might have to tweak that value, since splitting the book into more than 255
files might cause troubles in some players (the id3v1 track number tag can
only go up to 255.) After that, each chunk is processed by text2wave and
the resulting audio stream is sent directly to 'lame' through a pipe. The
encoding is performed with the mw-us
preset, which is mono ABR
40 kbps average at 16 kHz. That should be enough, since Festival outputs a
voice sampled at 16 kHz by default. You can leave it as it is, unless you
are using a voice synthesizer with a different sampling rate. Refer to
lame --preset help for optimum settings for different sampling
When you input the artist or title, do not forget to quote the string if it includes spaces; for example:
ps2mp3 -a "This is the author" -t "This is the title" my.pdf
Next, we are going to see how to convert to an audio file from the most common format: HTML.
#!/bin/sh - #requires lynx, festival and lame if [ "$#" == 0 ]; then echo "Usage: echo $0 [-a author] [-t title] <html file1> <html file2> ..." exit 1 fi while getopts "a:t:" option do case "$option" in a)author="$OPTARG";; t)title="$OPTARG";; esac done shift $((OPTIND-1)) count=1 for htmlfile in $@ do section=`expr match "${htmlfile##*/}" '\(.*\)\.htm'` lynx -dump -nolist $htmlfile | text2wave - | lame --ta "${author:-html2mp3}" \ --tt "$count. ${section:-html2mp3}" --tl "${title:-html2mp3}" \ --tn "$count" --tg Speech --preset mw-us - ${section}.mp3 #rm /tmp/est_* count=`expr $count + 1` done
The first part of the script, up to line 16, is about extracting the optional parameters from the command line. From line 19 we are going to perform a loop on the list of all HTML files, the remaining arguments given at the command line. On line 21, "${htmlfile##*/}" strips out everything up to and including the last "/" character - useful if we are dealing with URLs or a directory path - so only the filename remains. Then the '\(.*\)\.htm'` regular expression takes care of the extension of the file so the variable section holds only the stem of the file. It will be used to tag and name the resulting MP3 files.
Line 22 is really the heart of the script: first, 'lynx' takes an HTML
file as input and dumps its text to stdout. That output is piped to
'text2wave' and converted into a WAV-encoded stream, which is then piped to
'lame' to be encoded with the mw-us
preset and id3-tagged with
the artist/title/speech genre.
Note that the script can also take URLs as arguments, since they are directly sent to lynx.
This html2mp3
script is going to be
very useful for our next step, which is converting from CHM to MP3.
CHM files are a proprietary format developed by Microsoft, but basically they are just compiled HTML files with an index and a table of contents in one file. Their use as an ebook format is certainly not as widespread as HTML or PDF, but as you will see, it is pretty straightforward to convert them to audio files once you have the right tools.
#!/bin/sh - #requires archmage and html2mp3 if [ "$#" == 0 ]; then echo "Usage:" echo " $0 <chm file> [-a author] [-t title] <html file1> <html file2> ..." exit 1 fi while getopts "a:t:" o do case "$o" in a)author="$OPTARG";; t)title="$OPTARG";; esac done shift $((OPTIND-1)) archmage $1 tmpchm find tmpchm -name "*.htm*" -exec html2mp3 -a "$author" -t "$title" {} \; rm -fr tmpchm
is a Python-based script that extracts HTML files from
CHM. You will need to have Python installed to get it to run.
Unlike 'ps2mp3', 'chm2mp3' does not require an arbitrary decision on where to split the book: every page compiled into the CHM file becomes its own audio file. All we need to do is extract these pages with 'archmage' and convert them with 'html2mp3'.
We are using the find command to recursively search for HTML files in the CHM book that we extracted, since sometimes the HTML files are stored in subdirectories inside the CHM. Then, for each HTML file found, we call 'html2mp3'.
Remember that it can take a while to encode several dozen pages of text to speech and then to MP3. But you do not need to encode a full book to start uploading and enjoying it on your portable player.
Another recent article on Festival and TTS synthesis software
JavaOne was huge this year, with 15,000 conference attendees and over 200,000 on-line visitors. The world's biggest Java Developer event got lots of attention, but for more than just its attendance numbers. Besides deep structural changes to simplify the Java programing paradigm, Sun dipped more of its corporate toes into the waters of Open Source Software after its recent release of its flagship Solaris OS under the CDDL (Common Development and Distribution License).
While Java isn't free of Sun licensing encumbrances, more of it is more open to the Java developer community and key Sun software efforts are becoming OSSw projects. Leading the trend is the next version of Sun's Java Application Server, to be called Project Glassfish. This is a contribution of over 1 million lines of code! Sun's current developer group will seed the project under CDDL. Developers can view the latest daily updates, contribute to fixes and features, and join in discussions at http://glassfish.dev.java.net.
Sun also is sharing its Java System Enterprise Server Bus (Java ESB) under the OSI-approved CDDL license [ also being used for Sun's OpenSolaris project ]. While the idea of an ESB isn't new, this is the first major effort that will be OSSw-based. ESBs are based on the Java Business Integration (JBI) specification (JSR 208).
And if that isn't interesting enough.... Sun is donating 135,000 lines of collaboration-focused communication source code from its Sun Java System Instant Messaging and Sun Java Studio Enterprise products for use by the entire open source community on NetBeans.org.
The collaboration software, which was demoed both at a Keynote and at the free NetBeans Developer Day that proceeded JavaOne, is designed to increase productivity by enabling Java developers to dynamically work together anywhere around the world. It also offers corporate types a roll-their-own IM app. Both demos worked fine, but your mileage may vary.
That free NetBeans Day may have been a bit of self-promotion, but the sessions were decent and the demos were later repeated at JavaOne. Included was a very nice looking Java-based software CD player that also works nicely and is downloadable at the NetBeans web site.
Sun is also making previews of the next versions of Java available to allow greater community contributions. And Sun is simplifying its hefty naming scheme ["Java 2 Standard Edition version 5.xxx"] to just Java SE 5 [or Java EE 6]; the '2' is gone. And the release versions will not be dotted in their names. That will save some ink and even some paper [ older versions will remain unchanged. ]
Big numbers for Java: Sun claims that some 2 Billion devices have Java in some form, including 708 million mobile devices and 700 million desktops and an incredible 825 million Java-enabled smartcards! That's a whole lotta of Java.
Japanese telcom NTT/Docomo is spending a lot on Java too. Some 60% of the billion dollars its investing in new service and software development will be Java-based. This will include their 'Star' project, aimed at building the next generation Java phone runtime. There was also a new mobility kit for NetBeans developers, if you are working on embedded Java.
IBM announced that they will officially support Apache Geronimo as an equal
but lightweight application server alternative for its app server,
WebSphere. IBM has been an active contributor to the Geronimo project, and as
part of that they will donate several Eclipse plugins to speed up J2EE
development. Robert LeBlanc, IBM's WebSphere General Manager, speaking at
a keynote, noted Geronimo's status for IBM and stressed the importance of
SOA [Service Oriented Architecture] for today's integration challenges.
[see more on Geronimo and the heavy use of OSSw by Java users in the BOF section of this report.]
Eclipse 3.1 was officially released after being announced at JavaOne. The new version allows users to streamline testing, create user interfaces for rich client applications, and enhance support for Ant build scripts. Also, NEC became the 100th organization to join the Eclipse Foundation.
Continuing with the developer-friendly, Open Source theme at JavaOne, BEA Systems is offering official support for both Spring and Struts frameworks running on top of WebLogic Server.
Oracle announced that it's JDeveloper J2EE development tool will be available for free and that they have partnered with the Apache MyFaces project. That was 'free' as in beer....
IBM and Sun announced a new and improved relationship - which is good for the entire Java community. After sparring a lot for recent years, they signed a new landmark agreement calling for an 11-year collaboration effort. It's actually an additional year on the current argreement plus 10 more years... so that's 11 years, but the point is that their collaboration on Java will improve. Sun's shift to a more Open Source friendly position probably placated IBM's desire for Sun to loosen its control over Java.
Sun reiterated its position: there would be more OSSw in the Java space over the next year. Would that include opening up the JVM??? That may be news for JavaOne 2006.
Jonathan Schwartz, President and COO at Sun, opened the first keynote address, titled "Welcome to the Participation Age", discussing the importance of 'participation' in building communities, creating value and new markets, and driving social change. To drive the point home, Schwartz added, "The Information Age is over." [Really?] He was, to be sure, referring to Sun's new branding that has a curvaceous, subliminal "S" that stands for "Share" and extends that term to mean OSSw, Developer communities and even the Wikipedia. Schwartz re-emphasized that Sun has always shared some of its IP going back to the founding days of Unix. But watch the replay of the keynote to judge for yourself.
Since all the keynotes are posted now - and were available by internet broadcast in real time - please check out the link: http://java.sun.com/javaone/sf/sessions/general/index.jsp
During the second keynote, Graham Hamilton, a Sun fellow and vice president, addressed advances planned for Java SE software over the two upcoming releases, a period of 3 years!
Hamilton offered developers an early taste of Java SE 6 software, which is
expected to ship in summer 2006, and invited them to contribute directly to
the future of Java by reviewing source code, contributing bug fixes and
feature implementations and collaborating with Sun engineers. Developers
can join the community at http://community.java.net/jdk.
The following Java SE 6 features are [or soon will be] available for
testing and evaluation at the JDK software community site on java.net:
On the Enterprise Java Beans [EJB] development side, there is a new spec that does away with the Container Managed Persistence scheme [CMP] and make EJBs much more like 'Plain old Java objects' [or POJOs]. This came about from a lot of discussion and arm-wrestling with alternative projects and frameworks, most notable Toplink, Hibernate and JDO. So there will be one single persistence model for both Java SE and EE going forward.
The new scheme makes extensive use of the new Annotations feature which allows for in-code specification of resources and dependencies. Although this approach is not without some controversy in the developer community, it should ease reading code and do away with complicated deployment descriptors and, perhaps, make the intent of a developer or team more obvious. See information on Annotations here: http://java.sun.com/j2se/1.5.0/docs/guide/language/annotations.html
Sun is also releasing support for integration with scripting languages over both Java 6 and 7 SE. A technical session - TS-7706 Scripting in the Java™ Platform - described the new scripting engine that is already available in beta format and will be included in Mustang, Java 6. It is based on JSR 223 and will support several scripting languages.
[I'm including session numbers and titles since most of the presentations can be freely downloaded now - see last section below.]
There were several sessions dealing with performance and security, and these were among the most heavily attended.
The Tuesday session on performance, TS-3268, Performance Myths Exposed, was one of the few actually repeated on the last day. It reviewed several strategies and tested these on small and large apps. It also compared 7 JVMs Against 6 performance hacks and summarized it:
- use of "final" does not help performance - in-lining is automatic
- try/catch blocks are [mostly] free
- use of RTTI is a marginal performance win at best - with maintenance costs
Also of note, in spite of an ungainly title, was TS-3397: Web Services and XML Performance and the Java™ Virtual Machine: What Your JVM™ Is Doing During That Long Pause When XML Processing, With Optimization Suggestions which highlighted some practical rules-of-thumb to speed XML-Java interactions:
In the area of new and novel, the good Doctor Bil Lewis from lambdacs.com offers the Omniscient Debugger [for free]. This was during TS-7849. This debugger collects "time stamps" of everything that happens in a program. The debugger runs from the command line and once data is collected you can navigate backwards in time to look at objects, variables, method calls, etc.
"This is the debugger that you have always dreamed about, but never thought possible," said Bil Lewis, who developed the ODB. "You can see which values are bad, locate them, and learn who set them and why. You don't have to guess where the problems might be. You don't need to set breakpoints or wonder which threads ran or which methods were called. If a problem occurred, you can find it. You don't ever have to rerun the program."
Expect to generate huge log files and have seriously degraded performance while the logger/debugger is running. Dr. Lewis estimated a hit of 1:2 to 1:40 or so. But you will have all the needed info to find out where the bug was introduced. And it's free... all in a single debugger.jar file.
New Security for Web Services, TS-7247, focused on both Java 5 and the forthcoming Java 6. New features beef up Java security with RSA public key encryption, triple DES support in Kerberos, XML digital signatures, a certificate creation API, and a multithreaded SSL engine. There are also indefinite plans to include a new Microsoft C-API, which would assist Sun's efforts to better interoperate with future Microsoft crypto offerings.
One of the best TS presentations I've caught was TS-3955, "Nine Ways to Hack your Web Application", which rated 5 stars by my lights -- complete, concise, interesting, informative, and with clear slides and a knowledgeable speaker. I overheard many developers praising it in lines for other sessions.
In the Very Cool category was the Sun SPOTS project, in conjunction with UC
Berkeley. This is a preparation for ubiquitous wireless nets of
nano-robots acting as remote sensors. The SPOTS are capable of autonomous
work and dynamic reprogramming. For instance, they could monitor light and
heat in office buildings after hours to cut energy waste. This is reported
in TS-8601 Java™ Technology and Smart-Dust: Building Intelligent
Sensor Networks.
These low power sensor devices are called motes or SPOTS:
The remarkable thing is that its all Java, including the device drivers [no C] and runs directly on the hardware. The JVM is J2ME-based and supports a multithreaded programming model. Here's a picture.
Also cool was Boeing's static display of its self-piloting drone in the Pavillion. It uses a 'real time' version of Java and can remain on station for more than 15 hours. Scott McNealy joked at a Keynote that Boeing wanted to fly it for a demo, but SF officials didn't want an aircraft flying itself inside a building. More information is here: http://www.boeing.com/defense-space/military/unmanned/scaneagle.html.
And for the TV and Movie junkies....
This was announced at a keynote. Next years' future Blu-Ray HD-DVD players will ship with Java inside. Blu-Ray is a new DVD format with up to 50 Gigabytes on a single disc. The format was developed to record high-definition HD video and for storing large amounts of data. Blu-Ray devices will have a network connection for SOHO use and value-added services. Several devices were on display at the Pavillion Expo showing classy 3D menus that made use of the black space above and below a letter-boxed movie.
There were almost 200 BOFs [Birds of a Feather sessions], almost as many as conference sessions, and only for 3 evenings, so the overlap factor was very high. Although there were only a handful in the 11pm hour, there were a lot of people hanging out past 10 pm. The conference organizers probably should have scheduled some of these for Thursday evening, after the last conference sessions, since dozens of BOFs occurred during the big conference bash - with lots of rock 'n' roll and beer - and that gave many attendees double conflicts.
Unfortunately, the presentations from the BOFs are not going to be posted on the JavaOne web site, so there is no second chance on this material. I'm just sorry I didn't catch more of them.
A solid BOF reported on the Open Source use by Java Developers. Albion Butters, a senior analyst at Evans Data, reported on a new study showing 80% percent of heavy Java users (using Java more than 50% of the time) and 73% of light Java users (less than 50% of the time) use open source software for development compared to less than 45% of non-Java developers. In addition, Java users have more confidence in Linux for mission critical applications with 80% having enough confidence to use it in such important deployments compared to less than 50% of non-Java users.
"Microsoft's .NET has established a slight lead in the overall development space over Java, but we have found that the situation reverses in the enterprise space with more development taking place in Java than in .NET, 60% to 56% respectively", Butters said. Also, the study, involving some 20,000 developers, found that heavy Java users write multithreaded apps ~80% of the time, vs. only ~30% for non-Java users. Evans Data provides market intelligence for the IT industry.
This was BOF-9187: "Sorting Out Java Technology Fact from Java Technology Fiction: Trends, Adoption, Migrations, and Key Issues facing the Developer Today and Tomorrow". See a slide HERE.
It should be worth looking up TS-7011, Architectural Overview of the Apache Geronimo Project. Although I couldn't fit that one into my schedule, I did attend the associated BOF. [Geronimo is an Apache project to produce an OSSw J2EE app server.]
Sometimes you go to a good BOF... sometimes its a really good BOF. In this case, the Geronimo BOF had a surprise announcement early on.
While Aaron Mulder gave a short status talk on the project, highlighting that they were almost ready to pass the J2EE TCK, he was interupted by team member David Jencks who carried an open laptop.
"Its all green!," Jencks shouted as he walked up to a smiling Mulder. Jencks carried his laptop around showing the result of the test suite – all green bars. He said that represented 23,000 test cases and it had been running for a very long time.
Mulder, with rising confidence, announced that NOW Geronimo is J2EE compliant and got a crash of applause. He and his team gave thanks to the many OSSw projects that had software incorporated into Geronimo, including Jetty, OpenEJB, Howl, etc. Although the test was passed, the developers explained that there were additional usability issues to clear up before the J2EE certification would be official [this was completed shortly after JavaOne 2005].
Since many of the developers at Geronimo are IBM employees, there was a BOF question asking to position Geronimo verses WebSphere. Mulder joked "Well, we just wanted to release a shoddy product that no one will want..." [ later there were snarky remarks from an IBM JVM engineer regarding Sun's JVM, showing the true state of the IBM-Sun partnership. But then this was a late BOF, and many of these guys had been working all day on the certification. ]
BOF attendees were also warned not to download the so-called milestone release -- it's outdated. Instead, they encouraged everyone to download the "unstable release" which is actually more complete and more stable. [ See, everything we knew is wrong.... ]
Sun is publishing a commemorative coffee table book that covers how the Java technology revolution got started and where Java technology can go in the future. The first 500 attendees to pre-order the book at the JavaOne got a free Java mug and will get a copy of the book autographed by James Gosling. And those signing up at JavaOne could have their names included in the book as members of the Java Community. Sweet perk!
The format of JavaOne was simplified this year by not having early AM session before keynotes and by holding fewer but larger sessions. Some rooms (but not all) were set up for overflow sessions, and those that were 'televised' live did not always start at the beginning of presentations. This also lead to longer and slower lines entering technical sessions.
The delay was partly due to the conference planners, since they made people line up for technical sessions and then required everyone to have their badge RFID tag read by a scanner. So, to get a decent seat, we had to line up immediately after leaving a session and wait for the entire 15 minute break time before they let anyone in. It was a bit like being back in High School.
They were in fact trying to find out the most popular sessions and which ones deserved repeating - and by late Tuesday they had added more RFID readers and were allowing folks to enter earlier. But I do remember lining up for a session which filled up and then being redirected to another line at the overflow room which wasn't allowed to enter until after the session was underway. [Grrr!]
Food also was much simpler, and less interesting, with box lunches and only served at a single large room in the Moscone Center. In contrast, in previous years there were 2 or 3 large tents set up outside in the park-like Yerba Buena Center with multiple buffet lines. That way, people could get in quickly, pick the items they wanted, and get seconds if desired. But this new arrangement was probably easier to plan.
I have attended many JavaOne conferences and have written about the many amenities in glowing terms. This year, with a new conference planning outfit, the standards slipped a few notches.
Snacks were clearly of lower quality. Only corn and potato chips and Rice Krispies' Marshmallow Bars [made with animal gelatin], with occasional pretzels. No energy bars, no health food, very little fruit and certainly no cookies or brownies! There was only a single coffee and tea service in the afternoon, but there were 3 regular sessions and then 4 hours of BOFs. I saw several attendees carrying in Starbuck's cups, probably because they couldn't wait for the late afternoon beverage service or needed a boost in the evening.
JavaOne originally set the standard for food and snacks at developer conferences. In this area, JavaOne has certainly fallen. Compared to SoftwareDevelopment and OracleWorld, this was a vastly inferior affair for food. But JavaOne is still a premier technical conference.
You might want to pack your own Cliff Bars next year. And bring a thermos of java juice....
Here's a short guide to more JavaOne materials:
• all papers - but you need to register with Sun's Developer Network:
You can also try the javaone home page if you have trouble:
• javaone keynotes
• sys-con.tv on java one...
Howard Dyckoff is a long term IT professional with primary experience at
Fortune 100 and 200 firms. Before his IT career, he worked for Aviation
Week and Space Technology magazine and before that used to edit SkyCom, a
newsletter for astronomers and rocketeers. He hails from the Republic of
Brooklyn [and Polytechnic Institute] and now, after several trips to
Himalayan mountain tops, resides in the SF Bay Area with a large book
collection and several pet rocks.
By Edgar Howell
Tired of hassles with printers not intended for Linux and the endless compromises they involve, I finally decided to buy a color laser printer with a network card. There were several factors involved in making this decision:
But the consequences of this decision were not trivial. SuSE (at current writing at 9.3, I'm at 9.2) has been installing CUPS behind the scenes for several releases. Since the printer commands are pretty much the same as those used under lprng, there never was any real need to learn much about CUPS. Well, not until the network printer arrived and then very quickly the fun began.
Just one example of the problems: although the documentation says that the password wanted when logging in to admin is the root password, that has never worked for me.
However, as usual, if you know what needs to be done, CUPS really isn't that difficult to work with. Assuming that CUPS has already been installed on the machine in question, here is my list of the steps to install a network printer on it under CUPS. You will need to do this on every machine that is to have access to this printer. Note that in the following, the installation instructions of the manufacturer are irrelevant.
Make sure you select a printer for which the manufacturer provides a PPD (Postscript Printer Definition) since only the manufacturer can produce the PPD needed to make optimum use of the hardware. Actually, this is important whether the printer attaches directly to a PC or via the LAN. The printer I selected didn't have a PPD on the CD-ROMs that came with it, but a little time searching the Internet pointed me at a file that had two - one for the black and white variety, and one for color.
As root, do the following:AuthType, AuthClass and AuthGroupName
cupsd : ALL
" to /etc/hosts.allow
/usr/sbin/lpadmin -p net_printer -E -m printer.ppd \ -v socket://192.168.0.1
printer net_printer is idle. enabled since Jan 01 00:00 system default destination: net_printer
Recent converts to Linux should note that a PPD is analogous to but quite different from the notorious driver. As with a driver, under CUPS one needs a PPD for the printer. But it isn't executable code that can make your system unstable. Perhaps better compared with a configuration file, essentially it just contains plain-text data that informs the print system (CUPS) what capabilities the printer has and how to format data accordingly.
On the other hand, each machine that is to send print jobs to the printer has to have the correct PPD, as is the case with a driver: the machine initiating printing has to send something to the printer that it can understand.
By following the above steps, it took me less than 15 minutes to enable a notebook under SuSE 8.0 to print via the network printer. And that includes the time it took to remove lprng and install CUPS from the distribution CD!
Keep in mind that this ignores about 99.99% of CUPS and is totally insecure. Anyone with access to your network could start print jobs wasting toner until the paper runs out.
But for a simple home system behind a firewall, it will enable your network printer under CUPS and buy you the time to learn all the things we've ignored for the moment.
Edgar is a consultant in the Cologne/Bonn area in Germany.
His day job involves helping a customer with payroll, maintaining
ancient IBM Assembler programs, some occasional COBOL, and
otherwise using QMF, PL/1 and DB/2 under MVS.
(Note: mail that does not contain "linuxgazette" in the subject will be
There are several templating systems for Python, but here we'll look at PTL and Cheetah. Actually, I lied; we'll focus on some little-known templating features of Quixote that aren't PTL per se but are related to it. These can be used to get around some annoyances in PTL. We'll also compare Cheetah against PTL/Quixote to see whether one of the two is more convenient overall, or which niches each system works best in. Both systems can be used standalone in Web or non-Web applications. You can download Quixote at http://www.mems-exchange.org/software/quixote/, and Cheetah at http://cheetahtemplate.org/. Install them via the usual "python setup.py install" mantra.
The Quixote documentation has a thorough description of PTL, so we'll just give a brief overview here. A PTL template looks like a Python function, but bare expressions are concatenated and used as the implicit return value. Here's an example:
def add [plain] (a, b): answer = a + b 'a plus b equals ' answer
Calling add(2, 3) returns "a plus b equals 5". Doing this in ordinary Python returns None; the two bare expressions are thrown away. To build an equivalent to this template, you'd have to use StringIO or build a list of values and join them. And you'd have to convert non-string values to strings. So PTL is a much cleaner syntax for functions that "concatenate" a return value.
The [plain] is not valid Python syntax, so you have to put this function in a *.ptl module and teach Python how to import it. Assume your module is called myptl.ptl.
$ python Python 2.3.4 (#1, Nov 30 2004, 10:15:28) [GCC 3.3.4 20040623 (Gentoo Linux 3.3.4-r1, ssp-3.3.2-2, pie-8.7.6)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> from quixote.ptl import install # Install PTL import hook >>> import myptl >>> print myptl.add(2, 3) a plus b equals 5 >>> myptl.add(2, 3) 'a plus b equals 5'
One of PTL's features is automatic HTML quoting. Suppose you had this:
def greeting [html] (what): "<strong>Hello, %s!</strong>\n" % what
A nice user types 'world' into a form and your function returns:
>>> print myptl.greeting("world") <strong>Hello, world!</strong>
But say a malicious user types '<script type="text/javascript">BAD_STUFF</script>' instead:
>>> print x.greeting('<script type="text/javascript">BAD_STUFF</script>') <strong>Hello, <script type="text/javascript">BAD_STUFF</script>!</strong>
PTL escapes it automatically in case you forgot to. How does it know which values to escape? It escapes everything that's in a bare expression and not defined literally in the function: arguments, subroutine return values, and global variables. To protect a string from further escaping, wrap it in an htmltext instance:
>>> from quixote.html import htmltext >>> text = htmltext("<em>world</em>") >>> print myptl.greeting(text) <strong>Hello, <em>world</em>!</strong>
In fact, the return value is itself an htmltext instance:
>>> myptl.greeting(text) <htmltext '<strong>Hello, <em>world</em>!</strong>'>
htmltext is mostly string compatible, but some Python library functions require actual strings:
>>> "The universe is a big place.".replace("universe", text) Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: expected a character buffer object
This is one of the annoyances of PTL. The other is overquoting. Sometimes you have to use str() and htmltext() to get around these. Sometimes this is a pain in the butt. It causes parenthesesitis, long lines, obfuscated code, makes generic modules dependent on Quixote, etc. At least htmltext dictionary keys match their equivalent string keys. But if you intend to use the dict as **keyword_args, you'd better str() the keys.
PTL's third annoyance is the import hook. It's "magic", it may break sometime, it doesn't play well with other import hooks, and it has a failed-import bug. (The latter two are probably Python's fault rather than PTL's.) The failed-import bug is that if you import a module that doesn't exist, the variable is set to None rather than raising an ImportError. This causes a cascading error later when you try to access an attribute of it, similar to a null pointer dereference in other languages. You just have to remember that if a variable is unexpectedly None, it may mean a failed import. (This bug happens only in some circumstances, but I haven't figured out which.)
When using PTL with ZODB, the Quixote docs warn to import ZODB before PTL. ZODB has its own import hook, and they must be installed in this order or you'll get errors. I discovered the same thing happens with Python's fcntl module on the Macintosh. fcntl doesn't have an import hook, but PTL's hook has an unexpected interaction that causes fcntl to fail. On Mac OS X 10.3 (Python 2.3.0), fcntl.so is in a separate directory along with other "C" extensions. After installing PTL, import fcntl finds the deprecated FCNTL.py due to the Mac's case-insensitive filesystem. This is a dummy module that has constants but no functions. So you try to do file locking and blammo! AttributeError. To get around this you have to import fcntl before PTL, or put the extension directory at the start of the Python path before importing fcntl. If you're doing this at the start of your application because a third-party module later uses fcntl, it can be confusing to future application maintainers. (Python 2.4 supposedly doesn't have this problem because FCNTL.py doesn't exist.)
When the import hook works, it works great. But you may be leery of it due to known or unknown problems. What alternatives are there? PTL creates a *.pyc file, so once the module has been imported you don't need the hook again unless the source changes. But *.pyc files aren't compatible between Python versions, and you may forget to import-with-hook after making changes. So what other alternatives are there?
PTL is built from components that can also be used standalone in ordinary Python functions. This is not covered in the Quixote documentation but can be deduced from the source. Our first example above translates to:
from quixote.html import TemplateIO def add(a, b): tio = TemplateIO() answer = a + b tio += 'a plus b equals ' tio += answer return tio.getvalue() >>> import mymodule >>> mymodule.add(2, 3) '2 plus 3 equals 5'
As you can see, it's similar to StringIO but with a cleaner interface. It also automatically converts the right side to a string. There's a flag to do HTML escaping:
from quixote.html import TemplateIO, htmltext def greeting(what): tio = TemplateIO(html=True) tio += "&" tio += htmltext("<strong>Hello, %s!</strong>") % what return tio.getvalue() >>> reload(mymodule) >>> mymodule.greeting("<javascript>") <htmltext '&<strong>Hello, <javascript>!</strong>\n'>
Here we have to explicitly htmltext() everything we don't want escaped. Is this better or worse than PTL? Is the TemplateIO syntax better or worse than PTL? That's for you to decide. I prefer PTL for some modules and TemplateIO for others. TemplateIO is also better for generic modules that shouldn't depend on the import hook. The TemplateIO class resides in quixote/html/_py_htmltext.py. (There's also a faster "C" version, _c_htmltext.c.) You can copy the module to your own project (check the license first), or write a simple non-escaping TemplateIO in a few lines of code.
_py_htmltext.py also contains other classes and functions used by PTL and TemplateIO: htmltext, htmlescape, and stringify. stringify is a function that converts anything to string or unicode, a kind of enhanced str(). htmlescape calls stringify, escapes the result, and returns a htmltext object. But if the argument is already htmltext, htmlescape doesn't escape it. So when we said htmltext protects a string from being escaped, we really meant htmlescape treats htmltext specially.
When you use one of htmltext's "string methods", it calls htmlescape on its arguments. (Actually it inlines the code, but close enough.) So where we used the % operator in greeting() above, it escaped the right side. This is a common idiom in programs that use htmltext: put the htmltext wrapper on the left side of the operator, and let it escape the arguments on the right side:
result = htmlext("<em>format string %s %s</em>") % (arg1, arg2) def em(content): return htmltext("<em>%s</em>") % content
Don't do this unless you really mean it:
result = htmltext("<em>%s</em>" % arg) # BAD!!! 'arg' won't be escaped.
It's usually most convenient to put the htmltext() call as close to the variable definition or import/input location as possible. That way you don't have to worry about whether it's been wrapped or not. This can be a problem for generic modules that would suddenly depend on Quixote, but again you can copy _py_htmltext.py into your project to eliminate that dependency.
quixote.html contains a few convenience functions that build htmltext objects. The source is in quixote/html/__init__.py.
htmltag(tag_name, add_xml_empty_slash=False, css_class=None, **attrs) href(url, text, title=None, **attrs) url_with_query(path, **attrs)
Here are some examples:
>>> from quixote.html import htmltag, href, url_with_query >>> htmltag('table') <htmltext '<table>') >>> print htmltag('table') <table> >>> print htmltag('/table') </table> >>> print htmltag('table', False, 'foo') <table class="foo"> >>> print htmltag('br', True) <br /> >>> print htmltag('div', False, 'chapter', style="border-style:raised", foo="bar") <div class="chapter" style="border-style:raised" foo="bar"> >>> print htmltag('img', src="foo.jpg", width="200", height="160") <img src="foo.jpg" height="160" width="200"> >>> print href("foo.html", "Foo!", name="foo") <a href="foo.html" name="foo">Foo!</a> >>> url = url_with_query("delete_user", fname="ben", lname="okopnik") >>> print url delete_user?fname=ben&lname=okopnik >>> print href(url, "Page 2") <a href="delete_user?fname=ben&lname=okopnik">Page 2</a> >>> input_dict = {'page': 2, 'printable': 'y'} >>> print url_with_query("display", **input_dict) display?page=2&printable=y
But what if you really want your template to be a large string with placeholders that "looks like" the final output? PTL is fine for templates with lots of calculations and small amounts of literal text, but it's less convenient with large chunks of text. You either have large multiline strings in the function, making the expressions hard to find, or you use global variables for the literal text. Sometimes you'd just rather use a traditional-looking template like this:
<html><head><title>$title</title></head><body> $content </body></html>
Cheetah does this. It has a users' guide (which I mostly wrote), so we'll just complete the example without explaining it in detail:
from Cheetah.Template import Template t = Template(file="mytemplate.tmpl") t.title = "Greetings" t.content = "<em>Hello, world!</em>" print str(t) <html><head><title>Greeting</title></head><body> <strong>Hello, world!</strong> </body></html>
Cheetah has many features we won't discuss here, but one feature it doesn't have is smart escaping. You can set a built-in filter that escapes all values, and you can turn the filter on and off at different points in the template, but you can't escape certain values while protecting htmltext values.
Well, actually you can if you write your own filter. [text version]
from Cheetah.Filters import Filter from quixote.html import htmlescape class HtmltextFilter(Filter): """Safer than WebSafe: escapes values that aren't htmltext instances.""" def filter(self, val, **kw): return htmlescape(val)
Instantiate the template thus:
t = Template(file="mytemplate.tmpl", filter=HtmltextFilter)
Or put this in the template:
#from my_filter_module import HtmltextFilter #filter $HtmltextFilter
Sometimes you want to put an HTML table in a Cheetah template, but you don't want to type all the tags by hand. I've written a table module that builds a table intuitively, using TemplateIO and htmltext. Here's the source. The module docstring has the complete usage, but here are a few examples:
import table # A simple two-column table with headers on the left, no gridlines. data = [ ('First Name', 'Fred'), ('Last Name', 'Flintstone')] print table.ReportTable.build(data) # A table with headers at the top. headers = ['Name', 'Noise Level'] data = [ ('Pebbles', 'quiet'), ('Bam-Bam', 'loud')] print table.Table.build(data, headers) # A table with custom tags. data = [ ('Fred', 'Flintstone', '555-1212')] td = htmltag('td') td_phone = htmltag('td', css_class='phone') tds = [td, td, td_phone] t = table.Table() t.table = htmltag('table', css_class='my_table') for row in data: t.row(row, tds) # Match each cell with its corresponding <td> tag. print t.finish()
The output is a htmltext object, which you can set as a placeholder value for Cheetah.
quixote.form lets you build forms in a similar way, and the same object does form display, validation, getting values, and redisplay after errors. I highly recommend it. Like everything else here, it can be used standalone without the Quixote publisher.
PTL and Cheetah use a non-tag syntax for replaceable values, so they work just as well for non-HTML output as HTML. Zope Page Templates (ZPT/TAL) and Nevow's template system, among others, use XML-style tags for placeholders. This limits their usability for non-HTML output. I prefer to use one template system for all my output rather than one for HTML and another for non-HTML, and I hate XML tags. Those who love XML tags may prefer ZPT or Nevow. Nevow has an interesting way of building replacement values via callback functions, which literally "put" the value into the template object. (I wrote about Nevow in a previous PyCon article.) More ZPT/TAL information is here. These all can be used without their library's publishing loop.
I hope this article gave you some ideas on the many ways you can structure a template in Python.
Mike is a Contributing Editor at Linux Gazette. He has been a
Linux enthusiast since 1991, a Debian user since 1995, and now Gentoo.
His favorite tool for programming is Python. Non-computer interests include
martial arts, wrestling, ska and oi! and ambient music, and the international
language Esperanto. He's been known to listen to Dvorak, Schubert,
Mendelssohn, and Khachaturian too.
By Pramode C.E.
The Mac Mini is a very compact desktop computer designed by Apple. Based on the PowerPC (PPC) G4 CPU, the machine is ideal for those who wish to experiment with GNU/Linux on a non-Intel platform. In this article, we will examine how to get Ubuntu Linux up and running on the Mac Mini. Assembly language skills on a RISC CPU like the PowerPC are very much in demand in the embedded-systems industry - and we shall use the PPC Linux system to do a bit of assembly language hacking!
The Mac Mini runs on a PowerPC CPU having a clock speed of 1.25GHz (a higher-end version is also available). Figure 2 shows the output of running 'cat /proc/cpuinfo' on my machine:
processor : 0 cpu : 7447A, altivec supported clock : 1249MHz revision : 1.2 (pvr 8003 0102) bogomips : 1245.18 machine : PowerMac10,1 motherboard : PowerMac10,1 MacRISC3 Power Macintosh detected as : 287 (Unknown Intrepid-based) pmac flags : 00000000 L2 cache : 512K unified memory : 256MB pmac-generation : NewWorld
There is a 40GB IDE hard disk, two USB ports, one firewire port, built-in sound and a "slot-loading" CD/DVD drive. The power supply, rated at 85W, is provided as an external 'brick'. The unit does not come with a monitor or keyboard - you have to provide them yourself. Both the keyboard and the mouse are USB-based. I had no difficulty getting my Microsoft USB mouse detected, but I had to try a few different brands before I got my USB keyboard working.
There are some minor hardware peculiarities - one is the absence
of an 'eject' button for the CD drive. If you are running Linux
or MacOS, software eject will work; otherwise, holding the mouse
button down during the boot process will do the trick. Another
idea is to get into 'OpenFirmware' (similar to the CMOS setup
on the PC) during the boot process by holding down the
keys and
then executing the 'eject cd' command. Booting from the CD requires
holding down the 'c' key during powerup.
Ubuntu Linux has a PowerPC edition; the CD image can be downloaded from http://ubuntulinux.org. The Mac Mini comes pre-installed with MacOS X in the single partition which occupies the whole of the hard disk. The first step, then, is to run the installation CD and get OS X into a smaller partition (say 20 GB). Once this is done, you can boot with the Ubuntu installation CD and create a few partitions for Linux to work with. The rest of the Ubuntu installation process will proceed very smoothly and you will have a MacOS X/Linux dual boot system working perfectly.
Ubuntu is a nice end-user distro; but developers will have to put in some effort to get their favourite tools working. I had to do an:
apt-get install gccto have 'gcc' working. I downloaded the 220.127.116.11 kernel from kernel.org and tried compiling it with
make menuconfigwhich failed because the 'ncurses-devel' package was missing. The problem was solved by getting
from a GNU FTP site
and installing it from source.
Once the kernel compilation process is over, you will see a file called 'vmlinux' under the root of the kernel source tree. This has to be copied to the '/boot' directory under a different name, e.g. 'mykernel'. PowerPC systems use the 'yaboot' boot loader whose configuration file '/etc/yaboot.conf' looks similar to LILO's config file. Here is what I added to my 'yaboot.conf':
image=/boot/mykernel label=mykernel read-only initrd=/boot/initrd.img append="quiet splash"The 'ybin' program has to be executed to install the boot loader.
The PowerPC is more of a processor specification rather than a processor. Originally developed by an Apple-IBM-Motorola alliance, there are a lot of processors in the market which can be called PowerPCs; the Mac Mini uses a processor called 7447A. PowerPC chips are often used in embedded devices as well as in high-end servers.
Understanding the architecture and the assembly language of a microprocessor is crucial in tasks which involve low level interaction with the machine - like designing/debugging operating systems, compilers, embedded applications, etc. The Mac Mini running GNU/Linux can be used by universities and engineering colleges to provide computer architecture education to its students. We shall examine the basics of PowerPC assembly language programming in the rest of this article, mostly with a view towards understanding the code which GCC generates.
The PowerPC is a Reduced Instruction Set Computer (RISC). All instructions are encoded uniformly in 4 bytes and the only instructions which access memory are load and store instructions. There is a large register set consisting of 32 integer registers, 32 floating point registers, a condition register (CR), a link register (LR) and a few others. Programmers familiar with the x86 instruction set will note the absence of special registers like the stack pointer - the idea is that one of the general purpose registers itself can be used as a stack pointer. An Application Binary Interface (ABI) defines the conventions to be adopted; the SVR4 ABI, which ppc32 Linux follows, requires GPR1 (General Purpose Register 1) to be used as a stack pointer. Also, the ABI requires arguments to a function to be passed in registers starting with GPR3. A function can freely modify GPR3 to GPR12 - the caller is expected to save them if necessary.
Listing 1 shows a simple assembly language program. Let's see what each of the instructions does.
The instruction:
li 4, 0x10loads the immediate (constant) value 0x10 to the general purpose register 4; x86 programmers may be bothered by the use of pure numbers to represent registers rather than more meaningful names like r0, r1 etc. The instruction:
add 4, 4, 5may be thought of as doing the algebraic operation:
r4 = r4 + r5That is, sum the contents of general purpose registers 4 and 5 and store the result in GPR4. The instruction:
addi 4, 4, 5does the operation:
r4 = r4 + 5ie, simply add the constant value 5 to contents of register r4.
The 'stwu' (store word and update) instruction is a bit tricky. The general format is:
stwu rS, d(rA)The instruction stores the contents of register rS into a memory location whose effective address has been computed by taking d+rA. At the same time, rA is updated to become equal to the effective address. Note that the general purpose register R1 is taken to be the stack pointer, so 'stwu 1, -16(1)' stores the contents of the stack pointer register to a position at offset -16 from the current top of stack and decrements the stack pointer by 16. A sample interaction with 'gdb' shows that this is indeed the case.
What remains is the instruction 'blr' which should be read as 'branch to link register'. The Link Register (LR) is a special register which holds the return address during a subroutine call. Our 'main' was called from a standard library 'start' routine; LR will have the address of the instruction which main should return to. Doing a 'blr' will result in execution getting transferred to the address contained in the Link Register.
The GNU Debugger helps us single-step through assembly language programs; we will also be able to examine the contents of memory locations and registers after executing each instruction. First, we have to compile the program like this:
cc -g listing1.sand invoke gdb:
gdb ./a.outHere is a sample interaction with GDB:
Breakpoint 1, main () at listing1.s:5 5 li 4, 0x10 Current language: auto; currently asm (gdb) s 6 li 5, 0x20 (gdb) s 7 add 4, 4, 5 (gdb) p/x $r4 $1 = 0x10 (gdb) p/x $r5 $2 = 0x20 (gdb) s 8 addi 4, 4, 5 (gdb) p/x $r4 $3 = 0x30 (gdb) s 9 stwu 1, -16(1) (gdb) p/x $r4 $4 = 0x35 (gdb) p/x $r1 $5 = 0x7ffff8e0 (gdb) x/4xb 0x7ffff8e0-16 0x7ffff8d0: 0x7f 0xff 0xf9 0x44 (gdb) s main () at listing1.s:10 10 addi 1, 1, 16 (gdb) p/x $r1 $6 = 0x7ffff8d0 (gdb) x/4xb $r1 0x7ffff8d0: 0x7f 0xff 0xf8 0xe0 (gdb) p/x $lr $7 = 0xfebf100 (gdb) s main () at listing1.s:11 11 blr (gdb) s 0x0febf100 in __libc_start_main () from /lib/libc.so.6The 's' (step) command is used for stepping through one instruction. We can print the value of a register, say, GPR4 by doing 'print $r4' or 'p/x $r4' (print in hex). The contents of a memory location can be printed by executing a 'x/4xb' command. We note that executing the 'blr' instruction resulted in control getting transferred to the location 0x0febf100 - this is the address which the Link Register (LR) was holding.
The GDB command 'disas' (short form for 'disassemble') can be used to view the assembly code in a better way - here is the output obtained by running 'disas main':
(gdb) disas main Dump of assembler code for function main: 0x100003d0 <main+0>: li r4,16 0x100003d4 <main+4>: li r5,32 0x100003d8 <main+8>: add r4,r4,r5 0x100003dc <main+12>: addi r4,r4,5 0x100003e0 <main+16>: blr
The 'objdump' command too can be used to disassemble the machine code.
Branching to a subroutine results in the return address being stored in the Link Register - if this subroutine calls another one, the current address in LR will be lost, unless it is saved on the stack. Listing 2 shows a simple C program and Listing 3 is part of its assembly language translation obtained by running:
gcc -S -fomit-frame-pointer listing2.cLet's try to work out the code line by line.
The first line of 'main' simply decrements the stack pointer by 16 and stores the old value at that location. We are basically building a stack frame to hold the local variables defined within the function. Let's say the initial value of the stack pointer is 1000; after the first line, it becomes 984. The next instruction, 'mflr 0' copies the contents of the link register to general purpose register 0 which is then stored onto the stack by the 'stw' instruction at a location whose address is found by adding 20 to the value of the stack pointer register r1 (ie, location 1004).
The next two lines copy the number 3 to r0 and then stores it at the location whose effective address is computed by adding 8 to the contents of r1 (ie, location 992); this is the variable 'm' defined in our C program. The 'load word and zero' (lwz) instruction loads the register r3 with the value of 'm' and executes a 'branch and link' to function 'fun'. The 'bl' instruction transfers control to the function 'fun' and at the same time loads the Link Register with the address of the instruction immediately after the 'bl' in 'main'. We note that the old value of LR (which is the address to which 'main' is to return to) is overwritten, but that is not a problem because we have already saved this value on the stack.
The function 'fun' sets up its own stack frame and copies the value it received in register r3 onto the stack thereby creating the local variable 'x'. This is then copied into r9, incremented and copied to r3 (the instruction 'mr 3, 0' copies the value in r0 to r3). The function returns by doing a 'blr' - the stack pointer is adjusted back to its initial value before the return is executed.
Back in 'main', the value in r3 (the return value) is copied to the variable 'm' stored on the stack. The old value of the link register saved on the stack is copied to r0 after which the 'mtlr' (move to link register) instruction transfers it to LR. The function then returns by doing a 'blr'. The entire sequence of events can be understood clearly by stepping through the code using GDB.
The 'arch/ppc/kernel/misc.S' file under the PPC32 Linux kernel source tree defines a data structure called a 'sys_call_table' which holds pointers to all the system calls defined in the kernel. Here is a part of this array:
.data .align 4 _GLOBAL(sys_call_table) .long sys_restart_syscall /* 0 */ .long sys_exit .long ppc_fork .long sys_readWe note that the address of the fork function is stored in slot 2 of this array - the system call number of 'fork' is therefore 2. It's possible to write a simple assembly language program which invokes 'fork' - the idea is to execute the 'sc' instruction after storing the call number in r0 and any arguments in r3, r4 etc. Listing 4 demonstrates the idea. The program goes in a loop (by using the 'branch' instruction, 'b') after invoking 'fork'. If we run 'ps ax' on another console, we would be able to see two copies of 'a.out' running - proof that 'fork' has indeed been invoked!
Listing 5 is a simple C program in which we store the address of a local variable in a pointer and then dereference the pointer to modify the pointed-to object. Listing 6 is part of the assembly language translation obtained by calling 'gcc -S -fomit-frame-pointer'. We see that the assembly code is not doing anything special. The situation is a bit different when we try to take the address of a global object. The problem is that because each instruction (opcode + operands) is encoded in 32 bits, it is impossible to store a 32 bit address as part of the operand of a PowerPC instruction - we will have to split the address into two parts and add them up in a 32 bit register using two instructions. Listing 7 is part of the assembly output that we would get if the variable 'i' in Listing 5 had been defined as a global.
Let's compile the code into an 'a.out' and execute the command:
nm ./a.out'nm' shows you the names and addresses of all the globally visible symbols in your program; on my machine, I see that the variable 'i' has been assigned the address 0x100108a8. Split up into two parts and expressed in decimal, the most significant 16 bits is 4097 and the least significant 16 bits is 2216. Coming back to the assembly language program, the two lines we are interested in are:
lis 9, i@ha la 0, i@l(9)A disassembled listing of the program displays these lines as:
lis r9, 4097 addi r0, r9, 2216The assembler has encoded the 'load algebraic' instruction as an 'add' which has the same effect; this is something very common in PowerPC assembly programming. The notation 'i@ha' results in the higher 16 bits of the address of 'i' getting extracted and 'i@l' yields the lower 16 bits. The 'load immediate shifted' (lis) instruction loads 4097 into the most significant bits of r9 and the add instruction simply combines it with the lower 16 bits of the address of 'i'.
PowerPC programs too are vulnerable to the same buffer overflow attacks so common on x86 architectures. A function saves the contents of the Link Register on the stack if it calls some other function; it is very easy to overflow a buffer and overwrite this return address. Listing 8 shows a C program in which we overflow the buffer 'a' - we are adding 12 to the contents of a[13]. Reading the assembly code produced by doing
cc -S -fomit-frame-pointer listing8.ctells us that
refers to the memory location where
the Link Register has been saved. Adding 12 to it results in the
function returning back to its caller (main) with the next 3
instructions skipped ('m++' takes 3 instructions and each instruction
is encoded in 4 bytes). So the program prints 57 instead of
58. Listing 9 shows the relevant
assembly code segment.
We have just had a glimpse into the fascinating world of assembly language programming - readers interested in Computer Architecture should refer to the book 'Computer Organization and Design - The Hardware/Software Interface' by Patterson and Hennessy to get some idea of the amazing techniques used by microprocessor designers to convert a slice of silicon to a marvel of engineering.
IBM Developerworks routinely publishes articles on POWER CPU architecture and programming. If you would like to learn how to do this, start off with an introduction to the PowerPC assembly language programming at http://www-106.ibm.com/developerworks/library/l-ppc/. There is also a short article on the Mac Mini from an embedded perspective at http://www-128.ibm.com/developerworks/power/library/pa-macmini1/. If you wish to load Debian on your Mac Mini, you might like to consult http://www.sowerbutts.com/linux-mac-mini/.
Many PowerPC CPU's come with a fast SIMD unit called the Altivec - refer tohttp://www-128.ibm.com/developerworks/power/library/pa-unrollav1/ to learn more about Altivec optimizations. If you are developing multithreaded applications, http://www-128.ibm.com/developerworks/library/pa-atom/ will tell you how to implement atomic operations in PPC assembly.
As a student, I am constantly on the lookout for fun
and exciting things to do with my GNU/Linux machine. As
a teacher, I try to convey the joy of experimentation,
exploration, and discovery to my students. You can read about
my adventures with teaching and learning here.
By Dale Raby
What does Linux need to do in order to supplant Windows as the dominant OS on the desktop? This is a legitimate question often asked, but never answered very well.
Part of this may have to do with the basic makeup of people working on an OS that is almost designed not to be profitable. Such individuals often do not think like capitalists. Perhaps it is time to start thinking that way.
Profit is not necessarily a dirty word. I do not hold Bill Gates in contempt because he is a millionaire many times over. He got that way by supplying a product. In that, he is no different from J. K. Rowling, now the richest woman in England. Why should the rest of us Muggles not do the same?
Perhaps a better model corporate citizen for us to examine might be Apple's CEO Steven Jobs. Aside from being somewhat of a crackpot (in good company, I might add), he too, supplied a product... and developed a market for that product where there had not been one earlier. As testimony to his success... how many of you cut your teeth (pun intended) on an Apple IIe or an early MacIntosh?
An interesting point about Apple in the early years is the fact that they designed software to work on one specific set of hardware products and marketed them both as a single conglomerate product. Since they did not have an XYZ Corporation's made-in-(insert country of contemptuous choice) ISA interface holographic display card in their hardware, they didn't have to worry about some kind of machine ghost materializing whenever anyone tried to use it with another manufacturer's tri-D manipulation device.
The Home User Desktop Machine Of the Future (HUDMOF) will be a conglomerate machine that supports only the hardware in the conglomeration. While other hardware might work, whoever builds the HUDMOF has no incentive to support hardware built and sold by a competitor... though if the Linux kernel is used, such support will be available at little or no cost. Also, it will WORK with all the hardware items in the conglomeration.
We, the Linux Community, need to take a leaf from Capitalism's book and start competing for the desktop market. How would we compete? Well, price point is one thing. Free is pretty hard to beat... but there is no reason why we cannot sell it and make a profit. What is sold is not the OS itself, but rather, customer service. Having had my head bitten off from time to time asking dumb questions on various lists (you know who you are), I can say that we could all improve our people skills.
You sell customer service by either offering it with the price of the boxed distribution, or the download. You could, I suppose, offer it as a separate option a la LinuxCare. You could also use the OS to sell your hardware, with the OS pre-installed on it. What to sell and how to sell it depends upon the business model you are shooting for. In any case, as the OS itself is open-source, you HAVE to sell something else to make a profit.
Another point is reliability, which Linux excels at, once it is set up. This is something that is a real advantage over Windows. We should exploit that advantage before it disappears. Remember, Longhorn is on the horizon. Windows 98 was an improvement over Windows 95, and Windows 2000 and ME were improvements as well. Most probably Windows XP followed that trend (I don't own a copy) and Longhorn will as well.
The HUDMOF will be reliable.
Security... need I even mention that one? I am a paranoid individual about my own system. I run a Linux Floppy Firewall on a separate machine. IPTables has instructions to drop everything I do not specifically request. The Windows machines I maintain in my house are all behind this firewall as are the Linux boxes... and as will be the Apple Newton when I get it hooked up. I don't use wireless. Why give crooks an even break? Physical security consists of locked doors and a former soldier with a shotgun.
A system that is designed to have separate user accounts is definitely the way to fly, as far as I am concerned. I don't have to worry about anyone getting into my email or deleting an important document, and I don't have bookmarks for Bild Magazine, Days of Our Lives, Pokemon, or any other websites I never visit cluttering up my list. Those are in the home directories of other users where they belong. Others might prefer a single user setup. To each his own.
For those who prefer separate accounts for each user in the household, passwords and separate home directories make for good virtual neighbors. The HUDMOF should have multi-user capability built-in... and iron-clad security.
Ease of installation/use. Now we have a problem. I've played with Red Hat, Fedora, Mandrake, Debian, Gentoo, Knoppix, Storm, DamnSmallLinux, and SmallLinux. Some of these distributions are extremely easy to use, most notably DamnSmallLinux and Knoppix. Others, most notably Gentoo and Debian require... hmmm... actual intelligence.
Now, a true geek might say something like "to Hades with all those GUI wimps who can't understand how to use fdisk to partition a hard drive!" This is, however, short-sighted in the extreme. "Those GUI wimps" are the ones who will be spending their hard-earned dollars and/or valuable time. They need to be courted, not snubbed.
Steve Jobs and Bill Gates both supplied a product that met a demand. They are continuing to do so. That is how to put Linux on the desktop, by supplying a demand, and a part of that demand is going to be a certain amount of "hand-holding".
The Linux Community has been trying to sell Linux for more than a decade now. Ralph Waldo Emerson once said: "Build a better mousetrap and the public will beat a path to your door."
Dale Raby's Corollary to Ralph's Mousetrap: "If you have to beat a path to the public's doors, there is something wrong with your mousetrap."
So what might be wrong with our mousetrap? Why are people not migrating in droves to an OS that is more reliable, more secure, and being "sold" at an unbeatable price? What demand are we not supplying that Bill Gates and Steve Jobs are?
Part of it is simple customer service, as noted earlier in this article, or rather, the lack thereof, in the case of many Linux distributions/binaries. Not to point any fingers regarding my experiences in the early days... aber, sprechen Sie Deutsch?
I once called Apple about a MacIntosh 512K. I got to speak to an actual person who listened to my questions. She explained that Apple no longer stocked any parts or software for this fine antique, but referred me to Sun Remarketing. Microsoft also answered my questions politely and provided answers. Indeed, they maintain a vast database of solutions to problems... even with legacy hardware/software.
The HUDMOF should have first-rate customer service.
Even better than customer service would be quality control. If your quality control is up to snuff, you don't have to worry about customer service nearly as much. Ever had an application not do what it is supposed to do? Quality control issue. Applications should work as soon as they are installed with no tweaking. Many Linux applications DO NOT work without some CLI voodoo.
Mutt is a prime example of a potentially great binary that doesn't work as it should... "right out of the box". Before you can even start, you have to create a .muttrc file. This is not necessarily a bad thing as it allows the user to configure Mutt to behave exactly as he wants it to. But would it be too much to ask for a default ./muttrc with commented out instructions on what has to be entered where?
Then there are other applications that must work with Mutt in order to make a usable email package. You need to have Exim, Sendmail, Fetchmail and/or other MTA up and properly configured on your system in order to send and receive mail. Mutt documentation does not help with these very much... and the user manuals for these applications are definitely all in GeekSpeak.
Mutt is only being picked on as an example because of my never-ending frustration with training it. Realistically, it will not likely be found on many home user workstations. It will forever be a geek's favorite pet. Compared with the ease of use built-in with clients like Evolution, Sylpheed, and Pine, though, Mutt has much ground to cover in this specific area.
I have a long-time friend who runs a dairy farm in North-Eastern Wisconsin. He is still using a 486 PC running Windows 3.1. Why, one might ask, has he not updated his system?
The answer is not lack of intelligence. He and I played chess on the same high school team and took third at state. Considering the fact that we had the national champions in our conference, that was quite an accomplishment. He runs a profitable business with more in assets than the average computer store... and at a much smaller margin.
He is also not a Luddite. While you will find an occasional piece of antique machinery on his farm, the ones in use every day are modern and efficient. No Ford 9N tractor with a spark-ignition engine pulling a 2-bottom plow, but rather an Allis-Chalmers four-wheel-drive Diesel pulling a very large chisel plow. I recently helped to install an air suspension seat in the air-conditioned cab of one of these machines.
He also has on his farm several tools that date from his father's time, his grand-father's time, and even his great-grand-father's time. They range from hammers to shovels to blacksmithing tools to tractors and other farm implements.
Why has the milking stool not been replaced? How 'bout a carpenter's claw hammer? Maybe the Marlin model 1895 deer rifle in 44-40 WCF? Same reason the computer has not been replaced: they just work.
Windows 3.1 and MS-DOS, despite their limitations, were extremely robust operating systems. How often have you out there picked up a roadside scrounge machine and upon bringing it home and booting it up found Windows 3.1 happily rising to the occasion for whatever use you had for it? I've never had a 3.1 machine die on me... they all survived long enough to be either given away or parted out. A large portion of the reason for this, I suspect, was the fact that they were fairly simple and designed to run on a small subset of hardware components.
The aforementioned farmer, Greg will come in late at night after milking 80 cows, maybe delivering a calf or two, and fixing a broken manure spreader outdoors in below freezing temperatures while his wife holds the flashlight and hands him tools. It might be that his foot hurts because a 1200 pound animal stepped on it. Quite possibly he skinned his knuckles when a bolt-head broke off in the wrench. Almost certainly he got a bill earlier in the mail for fuel, feed, or veterinary services.
If, when he comes in late and wants to use his computer for some reason, (or just as likely, Diane, the long-suffering, frost-bitten farmer's wife) he wants to push a button, wait for it to boot, and then have it do the task he has set for it with no complaining. He isn't interested in excuses from a customer service rep or a computer tech at the local distribution point. (My favorite was always "Well, that's Windows!" ) He certainly does not want to be bothered with having to learn C, Ruby, Perl or Python in order to tweak some application and/or recompile a kernel from source.
Greg is a farmer. He knows how to get cows to produce milk. He can deliver calves even when they come out backwards. We once delivered one where the cow ended up with a prolapsed uterus and had to hold the cow down until the vet arrived. (Go ahead and try to hold a thousand pound plus animal down some day while her uterus is hanging out on the ground! It is an enlightening experience to anyone who thinks himself physically strong.) He knows how to plant seeds and rotate crops. He knows about manure management. What? You think manure manages itself? It's a commodity just like any other... and it has to be managed such that it produces maximum fertilizer and little, if any, runoff.
Now, I am sure that Greg could learn how to initiate all the tricks that Linux can do with a command line on a Bourne Again Shell. I am also sure he won't bother... he just doesn't have the time or the inclination. I'm quite certain that the rest of us would also rather that Greg keep on milking cows so that we don't have to have a milk-cow in the back yard, (remember, manure management on a small scale involves the use of a shovel and a wheelbarrow) though if you want one, I'm sure that Greg will sell you one!
Most home users are like Greg in some way or another. We use our computers for web-browsing, email, word-processing, scheduling , and finance management. Each of us might have other tasks we put it to... maybe video production, or, as in Greg's case, the lineage of his herd.
Most of us also have children. Educational software has its place, and there needs to be more of it ported for Linux. In the main, however, the Internet will be supplying more and more information for the education of our children.
Some children will take to a CLI and a green or amber screen like a duck to water... but most of them will not. They'll want the machine to do what they want it to, i.e.: allow them to compose a book-report. They aren't going to be interested in learning how to use Tex for that purpose.
One other difficulty has been buying a turn-key system. Now, until recently, one could not just go out and buy a computer with Linux installed on it. It is much easier to do so now than it once was... case in point: machines marketed by Wal-Mart running Linare Linux (for UNDER $200.00!) and IBM desktop machines offered with Red Hat Linux installed.
In order for Linux to be the desktop machine of choice for somebody like Greg the Dairy Farmer, it had better be available as a turn-key system. He has never installed an operating system, and really doesn't want to learn how. Thanks to IBM, Wal-mart, and a few others, this is now a viable option. The HUDMOF will be a turn-key system.
Updates are a practical necessity. Of late, one can avoid the dependency nightmares I used to encounter by the use of tools like YUM. To download updates, one should be able to click one button or enter one simple command. The HUDMOF will have that feature built in.
Likewise installing new applications should also be just that easy. Nobody likes to hunt down obscure packages that may or may not work properly with a certain flavor of Linux. Synaptic and Yum are great tools for package installation... but they are not complete. Try entering "YUM install newtonlink" into your command line.
Fedora's latest set of binaries cannot always be downloaded from certain mirrors because of compatibility problems. This really sucks. Quality control, Fedora! Standards!
Much has been written in the trade journals regarding "disk-less" systems. With the price of disk drives having huge storage capacities falling like Michael Jackson's popularity, this is not considered as necessary as it once was. It is still a viable model, however.
For small businesses, one only need purchase a single "big muscle" machine that acts as a file server, and runs applications. This machine can be networked with lesser machines... disk-less PC's or what are being called "thin clients"... and operated remotely using SSH or any one of several other remote desktop clients. The big muscle machine can run pretty much any distribution that meets the prime needs; Red Hat or Fedora, Debian, or name your favorite flavor. In the case of a home-user, the big muscle machine may not even be necessary.
The disk-less machines in this model need not be anything special, and any of them could serve the home user as the sole element, though there is no real reason not to have a full-featured machine in the basement other than expense. Now, obviously, one need not have a hard drive for this "disk-less" machine, by definition. One need not even have a CD/DVD drive. Modern flash memory, and probably other technologies on the horizon can easily handle the storage needs of most general users. Actual RAM is getting cheaper by the minute, and it is already quite inexpensive enough to easily build machines sporting more than a GB of memory. This is quite enough to load the entire OS into a ramdisk. Can you say "fast"?
The exception might be home video & sound production. Video requires huge storage and processing capacity, and if the end result is a DVD, then obviously a DVD-RW drive will be necessary. Even these difficulties could be managed with remote storage, or even home storage devices that are not in the machine.
If one can get away without any physical drives, one is well on the way to an engineer's dream; a machine without moving parts. There is no disk to spin up to speed, thus no extra power requirements for that, nor is there the need for a CPU fan in many cases or a cooling fan in the power supply. A simple radiator type cooling system with heat fins like a Briggs & Stratton lawn-mower engine has will suffice.
It is also quite evident that such a machine will be able to run with very low power requirements. I no longer drive an '82 Olds Ninety-Eight, I drive a '91 Ford Escort. I am considering converting my house to run on LEDs for illumination. My RCA tube radio is in the garage on a shelf while the solid-state electronic devices have taken over. Anybody see a trend? Look for that trend to continue.
The HUDMOF will be energy efficient.
Two Linux distributions really stand out in the disk-less model; Knoppix, and DamnSmallLinux. Both of these distributions are live-CD, Debian-based, and DamnSmallLinux could be considered a "hack" of Knoppix, though the principal developer would dispute that claim... and justifiably so. (Note: the latest Knoppix distributions will have an option for live CD and another intended for HD installation.)
One need only put the CD for each of them into the CD-ROM drive and turn the "damn" thing on. In most cases, all hardware is detected and configured properly during the initial boot process with no digital complaining of any kind. The one issue that seems, in my own experience, to be not so smooth with both of these distributions is that of printer setup. All peripherals should be detected and configured properly during the boot process... and that includes the printer. Now, it is fairly unusual for me to print anything these days, going paperless makes a lot of sense... but that is another issue to be dealt with later.
Most PCs can run either of these distributions, though there are greater memory requirements with Knoppix which is really quite full-featured compared to DamnSmallLinux. Also, the latest release of Knoppix will not run on some of my older hardware that the earlier version will. If you only have basic needs for a disk-less system, DSL will serve you quite well, and with a minimum of fuss. If you want more packages get the latest Knoppix live CD distribution.
Wyse makes one of their Winterm Thin Clients, the S50, available running Wyse Linux V6. I have no experience with Thin Clients, and am unsure if this machine would serve a home user or not. I suspect that it would under many circumstances. One would have to provide storage devices for it... either USB Iomega Zip drives or pen drives, other storage media, or, even better, an on-line server in a remote location equipped with high-end RAID devices, regular backups, and security administration.
I recently cobbled up a system for a neighbor running DamnSmallLinux on an IBM Pentium 100 machine. This machine has a web browser, an email client, a word-processor, and several other common applications. I installed the OS onto a hard drive I had laying around, but I would not have needed that if it had an Ethernet NIC installed. The machine will meet the needs of this man and his family for years to come, I suspect, and it was already an obsolete machine when delivered.
Had I wished, I could have made this a highly-efficient disk-less system with multiple interface ports in a physical size smaller than O'Reilly's book, Running Linux. As neither I nor my neighbor has any money, I decided to recycle hardware I was no longer using.
If a device could be built, in quantity, with item-specific off-the-shelf components, perhaps with an OS either on an old-fashioned ROM chip or a Flash memory module running a pared-down Linux kernel without superfluous drivers that would no longer be necessary, the dream of a computer in every home could at last be realized. Indeed, using cutting edge hardware such as that produced by Gumstix, with further development, it is conceivable that even a dirt-poor third-world slash-and-burn subsistence farmer could one day afford to purchase and run a solar-powered machine to expand his world and give some level of hope to his children that they might not presently have.
All computers need some kind of monitor. The latest trend seems to be LCD monitors, though many of us still use the old CRT monitors. I even have one made by Zenith capable of full color, amber, or green screens. CRT monitors are on the way out. They are stable, inexpensive, and as they are a mature technology, quite reliable. They take far too much power to operate, however, and they are too large and heavy.
LCD monitors are less expensive to operate, but more expensive to purchase initially. They can be made flat and take up far less space on the desk top. One of their problems is that children love to touch the screen... often damaging it. Autistic children especially like to see the weird patterns when they push their fingers against the screen.
A relatively recent technology is e-paper, which has to potential to supplant all the previous display technologies... at least until holographic display leaves the realm of science fiction and joins us in the real word. Sony, among others, has been developing this technology... and even using Linux in the process.
The HUDMOF will use an e-paper display.
Printers are crude and need to be replaced as soon as possible. There will, for the foreseeable future, still be a need for printed documents, but this is more and more to soothe the worries of the user than any other purpose. Printers are expensive to buy, expensive to operate, expensive to repair, and none too reliable due to the need to manipulate physical media with electro-mechanical devices.
Within a very short time, comparatively speaking, there will no longer be a demand for conventional printed matter. Newspapers and magazines will change to a subscription web site. Books will become e-books... though there will still be printed books for some time to come.
The last letter I ever actually wrote and snail-mailed was composed on a Tandy 600 and printed with an Epson dot-matrix printer. This will give you some idea of how long ago that was. Since that time, all my letters have been emailed. I almost never print physical documents any longer. All my writing is handled electronically and distributed that way as well. About the only things I still print are shipping labels for books I sell on Ebay. Now what was it I said about books in the previous paragraph?
The HUDMOF will eventually be without an interface for a printer. The few occasions where a printed document is needed will be supplied by on-line providers and snail-mailed out. The only exception might be, for a while, shipping labels for packages.
Probably the HUDMOF will be a conglomerate of many features mentioned here... and very likely several others I didn't mention. It will be:
Now, nobody has reached that ideal as of yet, but Sony, Wyse, Knoppix, Gumstix, and DamnSmallLinux represent some of the best implementations in this direction I have seen thus far. High end bloat-ware from Microsoft running on innumerable hardware platforms and even higher-end Apple products will not fit into this niche... though if Apple were to revitalize development on the Newton OS, and reduce the price, they might have something eventually. The Newton was truly the closest to the HUDMOF that has ever been actually produced... though the designers of the early Macs had the right idea as well.
I now lay down the gauntlet and challenge the manufacturers. This, I decree, will be the recipe for Linux conquering the desktop... and making somebody somewhere richer than Gates. All. You. Have. To. Do. Is. Build. It.
If you build it, they will come. IBM? Sony? Wyse? Gumstix? Klaus Knopper? John Andrews? You guys all listening? Steve Jobs? Bill Gates? Somebody build me a HUDMOF! Now just wait for the public to beat the path to your door, for you have fixed the mousetrap.
Dale A. Raby is an ornery old man who started out on the original IBM PC back
in the day of running MS-DOS programs while convalescing in Ireland Army
Community Hospital and working for Captain James. Upon release from that
particular episode of his military service, he bought a Tandy 600 laptop
which still works after a fashion.
He picked up a more "modern" computer in 1998 and began publishing a general
interest webzine, The Green Bay Web. Quickly discovering that Wind0ws 95 was
about as reliable as a drunken driver with sleep deprivation, he made the
conversion to Linux over the protestations of every member of his household. He
now uses Fedora Core and since discovering Yum, has managed to keep his systems
relatively up to date.
Dale is a graduate of the University of Wisconsin-Green Bay with a background
in photography and print journalism. He is also a shade tree blacksmith who can
often be seen beating red-hot iron into shape in his driveway. He has been
known to use hammers and other Big Tools to "repair" uncooperative computers.
He is a conservative WASP, abhors political correctness, and... not to be too
cliché... enjoys hunting and shooting. Yes, that is a shotgun. No,
it is not a rifle. Yes, there is a difference.
By Pete Savage
Network Intrusion is an important aspect of network security. There's a wide variety of Intrusion Detection Systems (IDSes) out there. While these are extremely useful to gather information about an attack, or the beginnings of an attack, e.g., a port scan, they can only inform us that an attack has occurred. What would be really useful is a system that actually blocks these attacks in real time. snort_inline is a system designed to do just that.
This article describes how to compile, install, and test snort_inline. snort_inline is a modification of the freely available snort package to allow inspection and subsequent rejection of network packets, assuming they meet certain predefined criteria. This constitutes an Intrusion Prevention System (IPS), instead of just Intrusion Detection.
So, how does an IPS actually work? The system loads a large array of signatures. These signatures take the form of a string of data characteristic of some particular type of attack. When a data packet enters the network, the IDS/IPS examines that data against its database of signatures. If the data match, then the IDS/IPS takes appropriate action. In the case of an IDS, the intrusion attempt will be logged, whereas, in the case of an IPS, the system can drop the data packet, or even sever the offending machine's connection.
To begin with, if you are running a Red Hat/Fedora system, you may need the source code for your system's installed kernel. This may be true of other systems, too; please see below for more information on why this is required. It is also useful to have a Web server running, as this article uses the Web service to validate snort_inline's behaviour. You should not attempt this on a production server - at least not the first time that you try this procedure.
snort_inline requires four packages to be installed in order to configure it on a Fedora Core 3/4 box. This may be true of other systems, too; please see below for more detail, later in the topic. We will assume all files are downloaded into /home/snort/; please replace this with your own download directory.
To begin with, you need the iptables source code. For reference, I used iptables-1.3.1 for this article. Once you have the source tarball, move it to /usr/src/, untar it, cd into its tree, and run 'make' with the install-devel option:
mv /home/snort/iptables-1.3.1.tar.tar /usr/src/ cd /usr/src tar xjvf iptables-1.3.1.tar.tar cd /usr/src/iptables-1.3.1 make install-develThis will install the libipq library, allowing snort_inline to communicate with iptables. iptables is responsible for accepting or rejecting packets on the network interface.
Next, you need to build and install libnet, which is a high-level API allowing snort to construct and inject packets into the network. The version of libnet I used was libnet-1.0.2a, as specified in snort_inline's docs. The newer version of libnet is, as yet, incompatible with snort. Follow the instructions below, once you have downloaded libnet-1.1.0.tar.gz:
mv /home/snort/libnet-1.0.2a.tar.gz /usr/src/ cd /usr/src tar xzvf libnet-1.0.2a.tar.gz cd /usr/src/Libnet-1.0.2a ./configure make make installProviding there are no errors, you can proceed to the next section. If at this stage you do find errors, you may need to install other packages. The third package required is pcre, the Perl-Compatible Regular Expressions library. For reference, I used pcre-6.1.tar.gz. Once you have this file downloaded, follow the steps below, to install pcre:
mv /home/snort/pcre-6.1.tar.gz /usr/src/ cd /usr/src tar xzvf pcre-6.1.tar.gz cd /usr/src/pcre-6.1 ./configure make make installProviding there are no errors, you can proceed to the next section. Important: On Red Hat/Fedora systems, you will need to perform an extra step before you can compile snort_inline. This has not been tested on other systems, but, if your build fails later with the error shown below...
In file included from /usr/include/linux/netfilter_ipv4/ip_queue.h:10, from /usr/include/libipq.h:37, from ../../src/inline.h:8, from ../../src/snort.h:38, from spo_alert_fast.c:51: /usr/include/linux/if.h:59: redefinition of `struct ifmap' /usr/include/linux/if.h:77: redefinition of `struct ifreq' /usr/include/linux/if.h:126: redefinition of `struct ifconf' make[3]: *** [spo_alert_fast.o] Error 1 make[3]: Leaving directory `/usr/src/snort_inline-2.3.0-RC1/src/output-plugins' make[2]: *** [all-recursive] Error 1 make[2]: Leaving directory `/usr/src/snort_inline-2.3.0-RC1/src' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/usr/src/snort_inline-2.3.0-RC1' make: *** [all] Error 2...you may need to perform the corrective steps below: The build fails because your glibc headers need to be updated [1], and this is why the kernel source is required, as stated above. To temporarily fix this problem, please make the following adjustments. This step assumes you have your kernel's source installed, and that it resides in linux-2.6.9. This directory is likely to change, depending on your kernel/distro version.
cd /usr/include mv linux linux.orig ln -s /usr/src/redhat/SOURCES/linux-2.6.9/include/linux/ linuxThis step can always be reversed at a later date, should problems arise. You now need to obtain the latest snort_inline package. For reference, I used snort_inline-2.3.0-RC1.tar.gz in this guide. Now, perform the steps outlined below.
mv /home/snort/snort_inline-2.3.0-RC1.tar.gz /usr/src/ cd /usr/src tar xzvf snort_inline-2.3.0-RC1.tar.gz cd snort_inline-2.3.0-RC1 ./configure make make installIf there are no errors, then congratulations: You have just successfully compiled and installed snort_inline.
cp /usr/src/snort_inline-2.3.0-RC1/etc/classification.config /usr/src/snort_inline-2.3.0-RC1/rules/ cp /usr/src/snort_inline-2.3.0-RC1/etc/reference.config /usr/src/snort_inline-2.3.0-RC1/rules/We are going to move the configuration and rule definition files to the /etc folder, where files of this type normally reside.
mkdir /etc/snort_inline cp /usr/src/snort_inline-2.3.0-RC1/etc/* /etc/snort_inline/ cp /usr/src/snort_inline-2.3.0-RC1/rules /etc/snort_inline/ -RSave the file and exit. Eventually, we are going to set up snort_inline to run as a daemon, i.e., as a background process, although it is perfectly conceivable that you may prefer to run it as a normal process. In fact, to begin with, we won't be running it as a background service, either: running non-daemon mode will let us view snort_inline's output, and ensure that it is running as expected, without any errors. We must now check /etc/snort_inline/snort_inline.conf to ensure that the rules pathspec is as required below. Load the file in your favourite text editor, and modify the line
var RULE_PATH /etc/snort_inline/drop_rulesto
var RULE_PATH /etc/snort_inline/rulesWe now need to create a directory for snort_inline, to log the malicious activity.
mkdir /var/log/snort_inlineBy default, all traffic flowing to the kernel and back to user space must be intercepted by snort_inline, to check for malicious network packets. The kernel accomplishes this by pushing the data into a queue using the ip_queue module. You can load ip_queue and verify its presence as follows:
modprobe ip_queue lsmod | grep ip_queueProviding you get see a line similar to the one below, ip_queue is running and ready to interface with snort_inline.
ip_queue 9945 0Next, iptables must be configured to send the traffic to ip_queue. You accomplish that redirection using the following line, which redirects all network packets destined for port 80 to the ip_queue module. If the server is running a Web daemon, then this is an easy way to verify that iptables is working. It is not recommended that you test this on a production server, as your Web users WILL experience downtime.
iptables -I INPUT -p tcp --dport 80 -j QUEUEIf you now try browsing a Web site hosted on the server from a different machine, you should notice that your browser hangs. This is because all packets are being routed to the ip_queue, and are awaiting release by iptables. Once snort_inline is running in background, all that traffic will be released to the Web server, which will reply to the user's request in the usual manner.
snort_inline -c /etc/snort_inline/snort_inline.conf -Q -N -l /var/log/snort_inline/ \ -t /var/log/snort_inline/ -vYou should see some text flash by, and snort_inline should present a message similar to:
__== Initialisation Complete ==__If so, congratulations; snort_inline is now running. Try making that connection via your Web browser again, and you should now see the Web page you expected. If you get a message similar to that below, then you forgot to load the ip_queue module:
Reading from iptables Running in IDS mode Initializing Inline mode InitInline: : Failed to send netlink message: Connection refusedBack on the snort_inline box, hit [ctrl+c] to end the current snort_inline process. It is now time to add a test rule so that you can see if snort_inline is actually working. In this example we are going to drop all port 80 activity. To do this, you need to edit /etc/snort_inline/rules/web-attacks.rules. Open it using your favourite editor, and add the following line before the first "alert" statement, but below the comments.
drop tcp any any -> any 80 (classtype:attempted-user; msg:"Port 80 connection initiated";)Note that all other lines in this file start with the word "alert". This means that snort_inline will only log and alert malicious packets: it WILL NOT DROP them. This will be addressed in a short while. Re-run snort_inline again with the following command:
snort_inline -c /etc/snort_inline/snort_inline.conf -Q -N -l /var/log/snort_inline/ \ -t /var/log/snort_inline/ -vTry once more to make that Web page connection. You may be required to hit [ctrl+F5] to force page refresh and prevent your browser using a cached version. Your request should now fail. Let us now quickly check the logs, to see if snort_inline captured the "malicious attempt." Back on the snort_inline box, hit [ctrl+c] once more to stop the snort_inline process, and use the following command:
cat /var/log/snort_inline/snort_inline_fullYou should be presented with an output sequence similar to the following.
[**] [1:0:0] Port 80 connection initiated [**] [Classification: Attempted User Privilege Gain] [Priority: 1] 07/03-16:56:24.401627 192.168.16.68:2433 -> 192.168.16.7:80 TCP TTL:128 TOS:0x0 ID:24295 IpLen:20 DgmLen:48 DF ******S* Seq: 0x1EB0AE32 Ack: 0x0 Win: 0xFFFF TcpLen: 28 TCP Options (4) => MSS: 1460 NOP NOP SackOK [**] [1:0:0] Port 80 connection initiated [**] [Classification: Attempted User Privilege Gain] [Priority: 1] 07/03-16:56:27.341326 192.168.16.68:2433 -> 192.168.16.7:80 TCP TTL:128 TOS:0x0 ID:24297 IpLen:20 DgmLen:48 DF ******S* Seq: 0x1EB0AE32 Ack: 0x0 Win: 0xFFFF TcpLen: 28 TCP Options (4) => MSS: 1460 NOP NOP SackOK [root@localhost 20050625]#If so, congratulations for the third time; snort_inline has successfully used your rule to drop the packets. The string "Port 80 connection Initiated" was the line you entered into web-attacks.rules, above. We can also view a more-abridged version, by issuing the command
cat /var/log/snort_inline/snort_inline_fast
This should provide output similar to that shown below:
07/03-16:56:24.401627 [**] [1:0:0] Port 80 connection initiated [**] [Classification: Attempted User Privilege Gain] [Priority: 1] {TCP} 192.168.16.68:2433 -> 192.168.16.7:80 07/03-16:56:27.341326 [**] [1:0:0] Port 80 connection initiated [**] [Classification: Attempted User Privilege Gain] [Priority: 1] {TCP} 192.168.16.68:2433 -> 192.168.16.7:80 [root@localhost 20050625]#
In order to use snort_inline effectively, you must now remove the drop rule inserted earlier. Edit the file /etc/snort_inline/rules/web-attack.rules, and prepend # to the line you added earlier, making;
drop tcp any any -> any 80 (classtype:attempted-user; msg:"Port 80 connection initiated";)
#drop tcp any any -> any 80 (classtype:attempted-user; msg:"Port 80 connection initiated";)
The last step is to modify all the rule files, turning alert rules into drop rules. This can be done with a simple command, which must be typed out exactly. If you are unsure, please make a backup of the rules folder before you type this command, something that should be done as a matter of practice.
cd /etc/snort_inline/rules/ for file in $(ls -1 *.rules) do sed -e 's:^alert:drop:g' ${file} > ${file}.new mv ${file}.new ${file} -f done
The last thing to do is run snort_inline as a daemon with the line below, the only difference being the presence of the "-D":
snort_inline -c /etc/snort_inline/snort_inline.conf -Q -N -l /var/log/snort_inline/ \ -t /var/log/snort_inline/ -v -D
Congratulations: you have just installed a working IPS. For completeness's sake, the following instructions demonstrate how to stop snort_inline and return your system to normal operation. Be advised that you can alternatively accomplish this by simply rebooting the machine.
To stop snort, as it is now running in daemon mode, we need to find its process ID number, and then issue a kill signal. To do this, run the following command;
ps aux | grep snort_inline
This should present you with output similar to that below; the number we are looking for is the "15705":
root 15705 1.1 21.8 31184 27464 ? Ss 22:37 0:01 snort_inline -c \ /etc/snort_inline/snort_inline.conf -Q -N -l /var/log/snort_inline \ -t /var/log/snort_inline -v -D root 15727 0.0 0.5 3760 720 pts/0 S+ 22:39 0:00 grep snort_inline#
You can now go ahead and issue the kill command, as follows, where the number following kill is the one obtained in the previous step.
kill 15705
This will exit snort, but ip_queue will still be receiving packets and disrupting network traffic flow. As previously stated, in this example, all port 80 traffic will be disabled. To re-enable this traffic, we must remove the iptables rule with the following command:
iptables -D INPUT -p tcp --dport 80 -j QUEUE
Your server should now resume normal network activity on port 80.
This article has been a primer on the world of snort_inline. Next month's piece will be dedicated to updating snort_inline's rules, writing your own custom rules, and creating a snort_inline startup script to enable it at boot-up.
[1] Rick Moen comments: I advise caution about fooling with one's kernel headers. The old advice to do this by fetching new kernel source and unpacking it to /usr/src/linux was always problematic, and has now been obsoleted by better and less breakage-prone ways. Short explanation: Your kernel header files used in compilation need to always be compatible with the installed libc; therefore, you should never fool with them, except by installing a new libc package that furnishes new, matching headers.
Long explanation: Some kernel header files get invoked from locations within /usr/include/linux, during compiles. Early in the history of Linux, someone implemented the seemed-good-at-the-time notion of not carrying such headers inside /usr/include/linux, but rather -- to save disk space, perhaps? -- to symlink from there to those same header files' locations within a kernel source code tree unpacked at /usr/src/linux. Unfortunately, as you maintained your system over time, newer kernel source trees' header files inevitably accumulated subtle incompatibilities with the installed C library's entry points. Eventually, compiles begin to fail for mysterious reasons.
The cause of this syndrome was understood early on, but the habit of symlinking headers to /usr/src/linux locations became so ingrained that it took until about 1999 to eradicate it from Linux distributions, despite Torvalds's repeated urgings and exhaustive analysis from the Answer Gang.
What the author calls "updating glibc headers" looks to this commentator like an instance of the "symlink madness" Torvalds and others tried for eight years to stamp out. I personally wouldn't go there. If "the build fails" because of header problems, I'm betting you induced those problems yourself through prior fooling with /usr/include/linux contents, and your real cure is to stop doing that and let your system header files remain the way your glibc package wrote them.
Pete has been programming since the age of 10 on an old Atari 800 XE.
Though he took an Acoustical Engineering degree from the world-renowned
ISVR in Southampton UK, the call of programming brought him back and he
has been working as a Web developer ever since. He uses both Linux and
Windows platforms. He still lives in the UK, and is currently living
happily with his wife.
By Mark Seymour
This was supposed to be a month in which I did some navigating of my own (I'm currently awaiting a hiring decision which will require me to, hopefully, relocate to the same port of call as the editor of this very publication), so I thought we'd look at navigation on the internet.
To get to this page, of course, you already had to click on a link from the table of contents for this issue of Linux Gazette. That required clicking on another link from the LG home page itself. That home page was acquired either by a bookmark from within your browser, or a prompting link displayed in an email.
These chains of links are so common now that we hardly notice them; I get dozens of emails a week from friends with URLs embedded in them and, if the context seems interesting, click on them without even reading the HTTP address.
[ This is, of course, very dangerous behavior - but it's very common as well. URLs can very easily be used as traps for the unwary: e.g, the HTML version where the link text is completely different from the link target; the "misspelled" URL that's one letter off from a bank site - and LOOKS exactly like that bank site as well; the "trick" URL such as http://microsoft.com\important\free\download\no\really@3515134258 (most, but not all browsers these days are too smart for this; when opened with, e.g. "links" or many version of Internet Explorer, the above will take you to http://redhat.com); etc. Caveat emptor... -- Ben ]
But it's when we finally arrive at a page whose contents we intend to explore, that internet navigation really takes over. The distinction is so significant that I'm going to assay some jargon creation here:
These are examples of internavigation we see every day:
Because of the commonly-accepted convention that blue text, especially when underlined, is intended as a link to Somewhere Else, we immediately roll our mouse over it and click without pondering what will happen: if it's blue and/or it's underlined, it had better take us somewhere when we click on it, right? But when nothing happens (because the linkage is broken or the designer underlined and/or made blue the text without intending it to be a link), we get startled, and then usually get pissed off. (The little gloved hand icon is a good indicator that something, blue or not, is a link, but it doesn't, alas, work on all browsers and all operating systems and all pages.)
But now you've internavigated to a particular page, like this one, and you want to move about, not only within the displayed page but among the pages of the site.
Anchors are a simple way of navigating a single page; you will often see the word Top or the phrases Back to top or Top of page used to bring you back up from a long descent into a page's content. (If you click any of these, you will go to the top of the page.) Text linked to anchors can also provide a way to move quickly to related material, whether on the same page or another page.
The reason to return to the start of the page, of course, is to provide access to navigation tools. Internavigation tools are typically icons or text buttons, which represent links to pages within the site or on other sites. Intranavigation tools, unfortunately, often look exactly the same; making them look different (especially from tools that take you out of the site) is tricky, but worthwhile.
Even if they don't have any graphic quality to them, linked-text tools are really buttons (these are just examples and don't really go anywhere, so don't bother clicking them, even though they're blue and underlined):
Home | About us | Contact us | Legalisms |
With some modest formatting, they begin to look more like 'real' navigation tools (don't click these either):
About us
Contact us
But what should they look like? Are they part of the 'design', or are they just HTML-generated buttons like these?
The other problem that comes up is, where to put them? Do you just run them across the top of the page, as these might be? What then happens when you want to add more (or, more properly, the client wants you to add more, a lot more, like maybe a dozen more)? Do you make them smaller? Run them in two lines? (Don't laugh, you'll see that farther along.)
Or do you start to stack them down the left side of the page? If so, should they be in their own frame, so that they always stay visible as you scroll down the page?
Home |
About us |
Contact us |
Legalisms |
A non-scrolling frame has its own awkwardness, of course, and seems to have fallen out of favor with many designers. But a list of buttons down the left side is almost a universal solution these days, as shown in these (half-size) examples (none of which are in non-scrolling frames, by the way):
The same issues apply to navigation bars at the top of the page, as shown in these examples (see, two lines!):
Running out of room everywhere else, sites are beginning to wrestle with navigation at the bottom of the page:
But for a look at some really exciting navigation issues, let's try weather.com (click here to go to a full-size version or to the actual page):
Now there's some visual complication! You've got (roughly, from the top) blue underlined links, button links, a data-entry box, a pop-up requiring a 'go' button, a reversed underlined page link, radio buttons, a selection list, a clickable image, blue underlined links, another selection list, another date-entry box with its 'go' button, blue underlined links in an unnumbered list, blue underlined links with clickable images, yet more blue underlined links, a data-entry search box with yet another 'go' button, and bottom navigation using many black underlined links, reversed underlined links, and blue underlined (though not in blue, just to be different) links. Whew.
This shows what we've grown accustomed to as 'conventions', even for links to other pages: traditional (and now almost quaint) blue underlined text, buttons, images, and text of varying colors and underlining. You can tout your ability to do CSS and 'handcoding' all you want, but if you can't decide what a link should look like better than that, I don't want to hear about it.
Oddly enough, we've gotten so used to information overload that (most of the time) we can focus on what's important to us, even in a page as complex as this one. On the other hand, why should we have to? Why does every page have to have access to every other possible page in the site? By my count, there are links to over one hundred other internal pages on that one weather.com page. That's like putting the entire table of contents on every page of a book, just in case...
If the two header bars shown above, after being carefully introduced on an earlier page, were merely used as links at the bottom to 'jump' pages carrying a list of the 80-odd other pages they represent, not only would it save a lot of page room (hey, every bit helps when you're paying for transmission or waiting for bandwidth), but reduce eye irritation immensely.
Okay, we're looked at several 'professional' web layouts, and seen a few constants:
My advice for internavigation and intranavigation tools is this: determine your internal conventions early and stick to them.
Some rules, for those who like rules:
So, you hate rules. If you're not going to follow any of my rules, make damn sure you define your links early on: "Links on this site are indicated by flashing green elves and/or tiny red bullets and/or photos of my dog". (Make sure you have good behavior tracking software installed, too, so you can watch users departing your site at high velocity...) If you're creating some totally 'personal' site, it may not matter. If you expect users to enjoy using your site, buy things from you, tell their friends about you (you have heard of viral marketing, right?), and come back again, better come up with your own rules that work. Remember, all anyone expects of your site is exactly what they want to do, not what your design wants them to do. Make it easy for them.
Top of page, just because I said you should.
If you've gotten this far, you're probably wondering about the title of this month's column. Besides being a swipe of a line from one of my favorite speeches in Shakespeare ("...for Harry, England, and Saint George!" from the battlefield scene in Henry V), it recognizes two people, either of whom ought to be the patron saint of web designers, Prince Henry the Navigator and St. Brendan the Navigator. (Are we seeing a navigation theme here?)
Prince Henry, the son of the King of Portugal in the fifteenth century, organized and bankrolled numerous expeditions which expanded both Portuguese influence and maritime knowledge along the western edge of Africa, ultimately leading to Bartolomeu Dia's voyage at the start of the sixteenth century that finally rounded the Cape of Good Hope and opened the ocean route to the riches of the East.
St. Brendan was, if the stories are true (and if you think they're not, I suggest you have some more whisky until you do), the first person to reach the Western Hemisphere from Europe in the sixth century (well before that other guy whose Day we celebrate merely for doing it a thousand years later), traveling west in a hide boat from Ireland. He is the patron saint of navigators, and with the right PR behind him might well have become the patron saint of the internet instead of this guy:
St. Isidore, the front-runner in the race to become the saint's medal on the dashboard of the Web, beating out the Archangel Gabriel and St. Bernadine of Siena (the patron saint of public relations) and St. Rita of Cascia (the patron saint of impossible causes) in a proposal to the Vatican by an all-Italian internet organization. (Go figure why they like some Italian guy over a nice Irish boy like St. Brendan...)
No matter who ends up being the patron saint of your internet, if you want me to write about some specific aspect of design, you gotta email me and let me know.
I started doing graphic design in junior high school, when it was still
the Dark Ages of technology. Bill Gates and Steve Jobs were both eleven
years old, and the state of the art was typing copy on Gestetner masters.
I've worked on every new technology since, but I still own an X-acto knife
and know how to use it.
I've been a freelancer, and worked in advertising agencies, printing
companies, publishing houses, and marketing organizations in major
corporations. I also did a dozen years [1985-1997] at Apple Computer; my
first Macintosh was a Lisa with an astounding 1MB of memory, and my current
one is a Cube with a flat screen.
I've had a website up since 1997, and created my latest one in 2004. I'm
still, painfully, learning how web design is different from, but not
necessarily better than, print.
These images are scaled down to minimize horizontal scrolling. To see a panel in all its clarity, click on it.
All HelpDex cartoons are at Shane's web site, www.shanecollinge.com.
Part computer programmer, part cartoonist, part Mars Bar. At night, he runs
around in a pair of colorful tights fighting criminals. During the day... well,
he just runs around. He eats when he's hungry and sleeps when he's sleepy.
The Ecol comic strip is written for escomposlinux.org (ECOL), the web site that supports es.comp.os.linux, the Spanish USENET newsgroup for Linux. The strips are drawn in Spanish and then translated to English by the author.
These images are scaled down to minimize horizontal scrolling. To see a panel in all its clarity, click on it.
All Ecol cartoons are at tira.escomposlinux.org (Spanish), comic.escomposlinux.org (English) and http://tira.puntbarra.com/ (Catalan). The Catalan version is translated by the people who run the site; only a few episodes are currently available.
These cartoons are copyright Javier Malonda. They may be copied, linked or distributed by any means. However, you may not distribute modifications. If you link to a cartoon, please notify Javier, who would appreciate hearing from you.
From Jimmy O'Regan
[Jimmy] Continued from last month
Shawn is an American spelling of Sean (which is not an English name, by the way, it's Irish. It does appear in Scotland, but IIRC, the Gaelic version is Ian).
[Sluggo] Ian means Sean??? I thought Ian meant John. Or does Sean mean John too?
The latter. Sean is an Irish mispronunciation of John
[Breen] Bingo.
Also Seamus == Hamish == James.
Give the man a "Do Unspeakable Things To Me, I'm Irish (For a Given Value of 'Irish')" t-shirt!
[Breen] Here in the States, my surname is always considered Irish. I'm well aware that in Ireland they'll tell you that it's English.
Nah. I thought it was Irish.
[Breen] It's Anglo-Norman in origin -- Moleyns (as in Moulin) making it a cognate of Miller.
[Sluggo] Is that like the "My weiner is lucky" T-shirts that appeared right before St Patrick's Day?
A friend in Dublin sent me a great St Patrick's Day card. It showed two businessmen with shamrocks and green and other "lucky" things all over their briefcases and suits, but they had "bah humbug!" expressions in spite of that.
Note: yanks don't send St Patrick's Day cards. At least none that I've ever heard of.
Um... that's the first time I've ever heard of a St. Patrick's Day card. Will those Hallmark fiends stop at nothing?
From Sluggo
http://www.joelonsoftware.com/articles/Biculturalism.html Review of The Art of Unix Programming by Eric Raymond (review by Joe Spolsky) Entire book online at http://www.faqs.org/docs/artu/index.html
The article talks mostly about the cultural differences between Unix and Windows; it says Raymond gets this wrong because he doesn't understand Windows culture, but still recommends the book for its general insights.
'I have heard economists claim that Silicon Valley could never be recreated in, say, France, because the French culture puts such a high penalty on failure that entrepreneurs are not willing to risk it. Maybe the same thing is true of Linux: it may never be a desktop operating system because the culture values things which prevent it. OS X is the proof: Apple finally created Unix for Aunt Marge, but only because the engineers and managers at Apple were firmly of the end-user culture (which I've been imperialistically calling "the Windows Culture" even though historically it originated at Apple). They rejected the Unix culture's fundamental norm of programmer-centricity. They even renamed core directories -- heretical! -- to use common English words like "applications" and "library" instead of "bin" and "lib."'
[Rick] Yeah, they're not people who senselessly put up with endless churn and mind-numbing complexity at the behest of a monopolist vendor; they're just plain folks working to help Aunt Marge in contrast to those luftmenschen Unix (especially Linux) people who aspire to actually be in charge of their computing. Joel and Co. are so tragically misunderstood I'm getting all misty-eyed, just thinking about it.
Yeah, Aunt Marge will never be able to figure out her TiVo or use Google, right, Joel?
You'll have to wade through a large amount of tedious and irrelevant argumentum ad hominem, probably included as filler because Spolsky has otherwise so little to say -- and, of course, none of even that residuum about (in contrast to Raymond's work) the key issue of where control resides, as Spolsky's crowd gave that up long ago without much thought.
I don't really mind the four minutes I wasted on that review, but in an ideal world I'd really rather have them back.
[Jimmy] Um... where? I see a lot of general arguments against the Unix approach, but not against Raymond personally. The closest to an ad hominem argument I saw was this:
"Whenever he opens his mouth about Windows he tends to show that his knowledge of Windows programming comes mostly from reading newspapers, not from actual Windows programming. That's OK; he's not a Windows programmer; we'll forgive that."
and, uh... that's true from what I remember of the text in question.
[Jimmy] Aha. Looked at the section of the text: http://www.faqs.org/docs/artu/ch03s02.html#nt_contrast
"NT has file attributes in some of its file system types. They are used in a restricted way, to implement access-control lists on some file systems, and don't affect development style very much."
Umm.... that's kinda true, for given values of 'true'.
NT doesn't use attributes in the POSIX sense, it uses separate file streams. Each file on NTFS is more like its own directory, and arbitrary streams can be added to each file without restriction (xattrs on Linux are restricted to 64k, BTW). Heck, they could even add automatic versioning and really show NT's VMS roots if they wanted.
"Most programs cannot be scripted at all. Programs rely on complex, fragile remote procedure call (RPC) methods to communicate with each other, a rich source of bugs."
Again, true for a given value of true.
Most programs can't be scripted in the Unix way - by parsing the output - but can be scripted using OLE Automation. This is where that RPC confusion comes in: it's actually a C++ vtable on the local machine, with an extra part that describes the type information for each function (like Java's reflection API), which removes the need to write a wrapper for each programming language as you have to do in Unix land. Windows comes with a DCE RPC implementation, and will automatically marshal OLE interfaces across RPC for free if you decide to call a remote machine, but otherwise there is no overhead for compiled languages, and a little for interpreted.
If the amount of times Unix has been cloned is a testament to how good an idea it was, bear in mind that COM has been cloned several times (OOo's UNO, Mozilla's XPCOM, GNOME's Bonobo, KDE's (now discarded) original component system, etc.)
[Rick] 1. Otherwise irrelevant swipe about "idiotarianism", a term Raymond had briefly attempted to popularise in the context of his politics blog.
2. Reference to "the frequently controversial Eric S. Raymond".
Note: Passive-aggressives in the technical community have been lately falling back on the term "controversial" to denote someone whom you wish to suggest is somehow unsuitable and doubtful without actually presenting any honest argument as to why. I caught a business-school professor from San Jose State University recently trying to pull that bit of gutter rhetoric on the OSI license-discuss mailing list against outgoing OSI general counsel Lawrence Rosen. It was a disreputable bit of trickery there, and it is here, too.
3. The juvenile, thrown-in inclusion of a hyperlink to Raymond's 1999 "Surprised by Wealth" slightly inarticulate burblings about (temporarily, as it turns out) having paper-only winnings in the stock market from the VA Linux Systems IPO. Even the Slashdot trolls eventually got tired of cruelly waving the "Gee, you thought you were going to get rich, huh?" line at Raymond, but Spolsky hasn't.
All of that gratuitous personal nastiness formed part of what Spolsky lead with in his initial paragraphs. You might not have noticed it, but I did -- and it both distracted from the distinctly limited merits of his review's real content and sufficed to convince me that the man's a raving jerk.
[Kapil] The analogy Japan<-> America = Windows/Mac<-> Unix is flawed.
There are cultural differences between the users for whom the Mac/Windows/Gnome/KDE folks design interfaces and the users for whom the Unix interface is designed.
However, it is possible and indeed imperative(*) for users of the first kind (whom Spolsky calls non-programmers) to make the transition (at their own pace) to the users of the second kind (programmers). (**)
The difference between Gnome/KDE and Windows is that in the latter case the interface puts up barriers to this transition.(***)
(*) But there is no such imperative for people from one part of the world to adapt/adopt food habits from another part of the world.
(**) The logic of the world as it currently works is that those who do not (slowly but) steadily improve their understanding/usage of the tools they use will soon become incapable.
(***) I cannot decide exactly where to put Mac OS X.
[Jimmy] I have to admit here that I didn't bother following the links from that paragraph, and going by the text, I thought it was a favourable review:
"The frequently controversial Eric S. Raymond has just written a long book about Unix programming called The Art of UNIX Programming exploring his own culture in great detail."
[snip cultural differences....]
"on the whole, the book is so full of incredibly interesting insight into so many aspects of programming that I'm willing to hold my nose during the rare smelly ideological rants because there's so much to learn about universal ideals from the rest of the book. Indeed I would recommend this book to developers of any culture in any platform with any goals, because so many of the values which it trumpets are universal."
Aside from your third point, though, I think you're reading a bit too much into it: the guy is writing for an audience who have either not heard of Raymond, or who would most likely have an unfavourable impression that he's referring to -- "Don't be put off the book because of its author".
[Rick] That's a generous interpretation, and it speaks well for you, but not for Spolsky.
All of those three points, however, have been popular standbys of a certain Slashdot-type ad hominem squad that's been showing up -- invariably relying on anonymous postings -- in pretty much any discussion of Raymond, his writings, or his software or the last seven or eight years: Spolsky gives every appearance of having cribbed his "amusing", take-the-subject-down-a-peg-or-two references directly from the gossipers.
Those gossipers had a field day with Raymond for promoting the "idiotarian" concept on his politics blog, and then more so when he made the mistake of listing that in the Jargon File (which entry he later removed, upon reflection). And there's no conceivable reason to cite that in a book review, other than to serve as a personal swipe.
[Jimmy] OK, I'm conviced, especially since I went back to the article and noticed the date.
While we're on the topic, I went by Wikipedia's article (http://en.wikipedia.org/wiki/Eric_S._Raymond) after I sent that last mail, my PC crashed, I went back, and... the section titled 'Criticism' had changed to 'Trivia' -- it seems there has been a very slow edit war going on over the past few days.
[John] Attacks of ESR aside, one slightly off-color aspect I noticed in the review was a cited quote from an exec at Red Hat, taken from Nov 2003, which stated that Linux was not yet ready to be considered as being on equal footing with that other OS in the regard of ease of install and use by non-tech savvy types.
............... So here we are, 20 years after Unix developers started trying to paint a good user interface on their systems, and we're still at the point where the CEO of the biggest Linux vendor is telling people that home users should just use Windows. ............... |
I followed his link to the source of the quote, and saw that it was published in Nov 2003, and that the article went on to say:
............... Szulik gave an example of his 90-year-old father going to a local retailer in order to purchase a computer with Linux: "We know painfully well what happens. He will try to get it installed and either doesn't have a positive experience or puts a lot of pressure on your support systems," he said. However, Szulik expects Linux to be ready in a couple of years after it has had time to mature. ............... |
I don't mean to assert that the more ubiquitous platform doesn't maintain the advantage for wide OEM support, but depending on the apps that the user is going to run, the gap has been narrowing steadily over time, and for an ever increasing number of home users, Linux makes a very adequate replacement for MSW.
The citation of that quote also seems a bit misleading, in that it's quite easy to assume that it was more contemporaneous, rather than nearly two years old, and in the context of technological advances, nearly two years is a long time.
[Jimmy] Erm... that review was published a month after the quote in question. (As I said in my last mail in this thread, I didn't notice the date either .
[John] Oops, missed it both places - could be time for the semi-annual cleaning of the spectacles.
From Jimmy O'Regan
From Jason Creighton
I was checking my mail, and noticed something interesting in fetchmail's output. Here's the relevant bit:
fetchmail: POP3< +OK Gpop 72pf4507421rna ready. fetchmail: POP3> CAPA fetchmail: POP3< +OK Capability list follows fetchmail: POP3< USER fetchmail: POP3< RESP-CODES fetchmail: POP3< EXPIRE 0 fetchmail: POP3< LOGIN-DELAY 300 fetchmail: POP3< X-GOOGLE-VERHOEVEN fetchmail: POP3< .
I say X-GOOGLE-VERHOEVEN and thought "what the heck is that?". I googled (Admittedly not a very good way to find something if this a huge conspiracy. <grin> for it on the web and on Google groups, but that only turned up mailing list archive posts where people were posting the output of fetchmail -v in an effort to get their mail working.
My next step was to see if the extension introducted any obviously named commands:
[jason@jpc ~]$ socat - OPENSSL:pop.gmail.com:995,verify=false +OK Gpop 71pf3749931rnc ready. X-GOOGLE-VERHOEVEN -ERR bad command [jason@jpc ~]$
I tried several other permutations: X-GOOGLE, GOOGLE, GOOGLE-VERHOEVEN. Each one returned the same error code.
So I wonder: What is this thing? Is it just some tag saying "Yes, this is Google's mail service"?
[Sluggo] Should've yahoo'd or msn'd it. That'll show them.
Actually, I tried Yahoo, which didn't return any hits. I'd forgotten about MSN. It didn't return anything either. It's indicative of something (Google's massive market share? Forgetfulness? I don't know.) that I couldn't think of any non-Google search engines other than Yahoo.
[Ben] It's that X-GOOGLE-VERHOEVEN extension. It sets a default state for search_engine_lookup() in your brain... you're doomed, doomed I tell you.
[Jimmy] Well, they are the only search engine with a moon mapping facility (http://moon.google.com - today's the anniversary of the first manned moon landing, but you guys knew that, right?)
[Breen] I certainly did. (You have zoomed all the way in on google's moon, right?)
[Jimmy] Nah, I'm on dial-up. I'll be sure to do so tomorrow when I get a chance to go to a 'net cafe, but I think I can guess what I'll see.
While we're on the topics of space and current events, James "Scotty" Doohan died today. http://en.wikipedia.org/wiki/James_Doohan
From Benjamin A. Okopnik
Heather pointed me to your site, including your photos.
[Sluggo] Are you going to bait us all and not give us the URL?
Nah, just you. I emailed the URL to every single other person on the list privately - in fact, everyone else in the world - just to leave you out of the loop and watch you do this jumping up and down act; it's far too amusing to miss. So, everybody except you is in on the joke.
Perhaps we'll all take pity on you if you do it long enough.
[Sluggo] Grumble, what do you expect from a guy who lives on a boat so he can make a fast getaway anytime.
"Fast getaway". On a 37' sailboat. Riiiight.
Average speed for non-planing hulls = sqrt(waterline_length) Top speed -"- : sqrt(waterline_length) * ~1.3 Ulysses' LWL: ~32 feet.
HINT: Sailboats do not have afterburners, ramscoops, or braking jets. Reentry speeds are whatever the crane operator feels is safe - i.e., somewhere around 1 ft./minute (no heat-resistant tiles required.) Andy Green and Thrust SSC have nothing to fear from wind-driven machines, and Chuck Yeager in his X-1 never got to experience being outrun and outmaneuvered by a schooner or a yawl.
We do, however, make trans-oceanic passages - something that 99% of powerboaters will never be able to do aboard their boat - and burn zero to minimal fuel in the process. We also don't have to rely on bad-tempered machinery that could leave us stranded at any second. There's also the fact that wind is free... and with the cost of gas nowadays, that speaks to a lot of people.
[Sluggo] Not a peep from you about hurricanes this time. I take it you were unaffected?
I'll be sure to let you know if one of them kills me.
[Sluggo] Or is your computer sending preprogrammed posthumous messages?
[Sluggo] On a similar line, from another James Hogan book Voyage from Yesteryear , chapter 11. A human is talking to a robot.
............... -- What kind of machine are you? I mean, can you think like a person? Do you know who you are? -- Suppose I said I could. Would that tell you anything? -- I guess not. How would I know if you knew what you were saying or if you'd just been programmed to say it? There's no way of telling the difference. -- Then is there any difference? Driscoll frowned, thought about it, then dismissed it with a shake of his head. ............... |
Mike, if you're trying to tell us a) that you're a robot, and b) that we won't be able to tell the difference, you're way behind the curve. I mean, look at that mechanistic Python language thing you use: obviously robot-only fare. I mean, good *grief!* The thing treats whitespace as if it was significant. What else would you have to know to say "Yep, this guy is a Venusian Zombie Killer Robot - run for your lives!"
What a lovely, perfectly English cottage (including the satellite dish!) - and what a magnificently malevolent-looking cat! I hope you don't mind me keeping a copy of that pic; he represents a certain visually-unambiguous ideal. ))
[Thomas] Hehehe. Not at all, you're quite welcome. It's a she, as it happens. "Mildred" is her name. She likes to hunt rabbits, mice, birds, and squirrels. I have seen twice now, while I have been here, two de-headed squirrels. :/ Yuck. She isn't ferocious. She meaows a lot, and takes a shining to me, as all animals seem to do. She has sharp claws though, so watch out.
Continuing on the photo theme, I have more of the coast (a mere mile and a half walk away, across the farmland) that I will try and upload to Heather -- but I am putting together a more coherent website with these images on, providing a running commentary. I'm hoping Mike Orr will appreciate it as well. I've hopefully done him a favour (I do not mean for it to be patronising or condescending in anyway) and taken a picture of a Caravan and a static-caravan for him to compare. (Mike knows what I'm rabbitting on about.)
[Sluggo] I've already forgotten what a static-caravan is. A trailer that's not built to be moved very often?
(This was from a word discussion. Apparently a trailer is called a caravan in England. Here a caravan is a mode of travel ("several vehicles travelling together"), not a type of vehicle. The Dodge Caravan notwithstanding. http://www.dodge.com/caravan
[Thomas] This connection I'm on now relies on tin cans, string, and some sort of goat sacrifice...
[Brian] That it requires goat sacrifice is one thing, that it requires "some sort" of goat sacrifice implies more than one type of goat sacrifice possibly necessary for certain 'net connections through BT (one presumes). That you KNOW that there's more than one type of goat sacrifice has me slightly concerned.
.brian (who's also glad to know you weren't in the wrong place that day...)
I find that curried goat makes for quite a good sacrifice - especially if I'm the one being sacrificed to. A touch of scotch bonnet sauce and perhaps a squeeze of "sower orange", and it will ameliorate my wrath and charm my savage breast...
[Thomas] Ah, a man that speaks from experience.
[Thomas] The route to the sea also follows the river Brad, which has lots of fish in. I want to go fishing now.
[Sluggo] Tell Brad hi when you meet it. Britian has such interesting place names, starting with the river Thames. And in bonnie Scotland: Lost, Wick, Tongue, John o' Groats, Thurso. Oh, and here's an interesting one, Baile an Or. (Is that the Gold Town? Or something named after me?
BTW, Vancouver has a skytrain station called Braid.
[Brian] That must have been one wicked track design...
[Jimmy] Heh. You need to get a copy of "The Meaning of Liff" by Douglas Adams and... erm... someone else. They took several place names from around Britain and provided definitions for them
[Pete] The someone else is John Lloyd, see http://folk.uio.no/alied/TMoL.html
[Sluggo] Heh, heh.
............... *SLUGGAN (n.)* A lurid facial bruise which everyone politely omits to mention because it's obvious that you had a punch-up with your spouse last night - but which was actually caused by walking into a door. It is useless to volunteer the true explanation because nobody will believe it. ............... |
[Rick] Which reminds me: My sweetie Deirdre Saoirse Moen and I will be visiting the place "The Meaning of Liff" defines thus...
............... GLASGOW (n.) The feeling of infinite sadness engendered when walking through a place filled with happy people fifteen years younger than yourself. ............... |
via a very brief sojourn in the familiar spot alluded to inside here...
............... AIRD OF SLEAT (n. archaic) Ancient Scottish curse placed from afar on the stretch of land now occupied by Heathrow Airport. ............... |
- ...to attend this event:
- http://www.interaction.worldcon.org.uk
Alas, we will not have time to wander elsewhere in the UK.
[Sluggo] Or as Forsyth's film That Sinking Feeling , which is set in Glasgow, says:
............... The characters in this film are entirely fictitious. There is no such place as Glasgow. ............... |
The film with that memorable line, "There must be something more to life than committing suicide."
From Rick Moen
Quoting Benjamin A. Okopnik (firstname.lastname@example.com): > It's *possible* that [foo] acted in what he thought was good faith.
(Name elided from the quotation to stress that I'm mounting the soapbox to make a general point that I hope will enligh^Wentertain.)
It costs nothing to postulate good faith about people one is talking about; in my opinion doing so is both good manners and superior tactics.
In the hypothetical edge case of having stone-hard evidence, ready to post and likely to be understood, it is still usually much more damning to cite the evidence without comment, and let listeners reach obvious conclusions on their own. Why? Because of an odd rhetorical effect.
If I tell you "X is an irredeemable jerk, and I'm going to prove it to you", you will tend to unconsciously set your mind to resist the sales pitch and dream up any possible reasons why you might remain unpersuaded. It's human nature; if we're pushed, we lean the other way, out of habit.
By contrast, if I just start talking in a matter-of-fact fashion without apparent axe-grinding about various uncontested facts about X's doings, and you're moved to comment "What a wanker!", you'll tend to hold that conviction pretty firmly because (or so you think) you arrived at it on your own. In fact, you might dig in and start trying to convince me *I'm* being too kind.
So, next time you see me being nice about someone, or even protesting other people's too-hasty condemnation of him, please remember that generosity of spirit might have nothing to do with it: It might be a devilishly clever Machiavellian intrigue in disguise.
See also: http://www.csicop.org/si/2001-07/criticism.html , especially points "2. Clarify your objectives" and "5. Let the facts speak for themselves."
From Sluggo
Sent in my usability article. I finished it last night but my Internet access went kaput. Both the ISP and Qwest said everything's fine. I'm wondering if it's a bad modem or bad Ethernet card. The light on the Ethernet card and modem blinks like there's no tomorrow, even after I turn the computer off, until I unplug it. Some new kind of hardware hackery? "Do you know what your Ethernet card is doing?"
[Heather] It's 10 pm, do you know where all 10 of your Mb are...
So I'll be semi-offline for a while. If you need to contact me for anything, call [phone number].
Song of the month: "On Any Other Day", The Police
............... My wife has burned the scrambled eggs The dog just pissed my leg My teenage daughter ran away My fine young son has turned out gay ... AND IT WOULD BE OKAY ON ANY OTHER DAY!!! ............... |
[Jimmy] And quote of the day, from Mil Millington's mailing list: "Fiona Walker is the only best-selling romantic novelist who has ever started talking to me in a bar about buying horse sperm off the Internet. (That's not really relevant, but I sensed you'd what (sic) to know it anyway.)"
[Heather] The fortune cookie of the moment was the lyrics from Dark Side of the Moon.
"...as a matter of fact, it's all dark."
Heather "still crunching and munching yes I know we're late" grabs my white-rabbit type hat and races back down the rabbithole again.
I had to go to the library to upload the article. Since I didn't have a floppy drive I was about to buy a USB stick, then I thought, "My camera is a mass storage device. Maybe I can upload an arbitrary file to it." And it worked.
[Jimmy] Yeah, I've done that with my camera, and the smart media card from my brother's portastudio. (Which reminds me -- I have to replace that. Turns out these things don't cope well with power failure
[Ben] The Geek Resurgens, ne plus ultra! Can't kill 'im with a stick!
Well done, Mike. Me, I'd have had to wind a bunch of wire on some iron cores, and hope that the library computer would accept a pair of car battery clamps as serial input.
[Jimmy] And heck, if the librarians have a problem with that, they can also double as a means of persuasion.
From Suramya Tomar
[Jimmy] Continued from last month
I finally got the chance to read this months edition of the LG and saw this interesting discussion about Playboy hosting mirror.
I had noticed it last year when I was trying to download something off cpan. I took a screenshot of it since I didn't expect anyone to believe me without it. If you are curious here's a link to that blog entry:
Just thought I should share that with you all.
[Jimmy] [ Sharp intake of breath ] You mean it set your desktop background for you too? That's what I call service!
Yup. If you want a copy of the background let me know.
BTW if you trying to get to the above site right now, you won't get through. 'cause some unknown reason my LVS (Linux Virtual Server) decided to reset to its default blank settings. I am trying to get in touch with the Tech Support but so far havn't heard anything yet.
So As a side note, does anyone know any reliable web hosting service? I want PHP, MySQL, Perl on the server with SSH access and a decent transfer limit. If anyone knows a good hosting service let me know.
From Jimmy O'Regan
From an interview with Dan "You're doing what with DNS?" Kaminsky (http://www.securityfocus.com/columnists/342)
............... Naive comparison is a real problem, and even things that seem to be "apples to apples" -- say, a comparison between the vendor-announced vulnerability counts of Microsoft Windows XP SP1 vs. Redhat Linux 9 -- fall apart the moment you compare what's in the box for both. XPSP1 ships with no databases, while Redhat ships with at least MySQL and PostgreSQL. Should Redhat be penalized for warning customers of potential problems that might be experienced on their platform, despite the fact that they didn't even write the software to begin with? When Oracle on XP has a vulnerability, Microsoft does not need to put out an advisory, instead Oracle does. Should Microsoft be referred to as a more secure platform because standard disclosure policies do not extend to announcing problems in software acquired entirely from a third party? Would Redhat suddenly become more secure if you had to download MySQL and PostgreSQL from their respective authors, with the requisite advisories coming from those authors and thus not counting from Redhat itself? Bad metrics encourage bad decisions. Those that compare naively encourage naive security. It's 2005; it's a little late for that. ............... |
From Jimmy O'Regan
Amusing, and topical:
Canadians have been ordered not to read books that were sold to them "by mistake" . Read that article, then don't buy any Harry Potter books. Everyone who participated in requesting, issuing, enforcing, or trying to excuse this injunction is the enemy of human rights in Canada, and they all deserve to pay for their part in it. Not buying these books will at least make the publisher pay. Unlike the publisher, who demands that people not read these books, I simply call on people not to buy them. If you wish to read them, wait, and you will meet someone who did get a copy. Borrow that copy--don't buy one. Even better, read something else--there are plenty of other books just as good, or (dare one suggest) even better. Making Canada respect human rights will be hard, but a good first step is to identify the officials and legislators who do not support them. The article quotes a lawyer as saying, "There is no human right to read." Any official, judge, or legislator who is not outraged by this position does not deserve to be in office. [snip spoiler] ............... |
[Neil] Sending out spoilers on mailing lists is guaranteed to upset someone. I assume RMS included it to make people who read it less likely to buy. I think it's an unpleasant tactic and it makes me less inclined to support him on this.
If any of the gang want to redistribute this article further, please snip the spoilers.
Whoops. Time of morning: I c 'n' p'd from the wrong tab.
[Brian] Interesting. The paragraph with the spoilers in it isn't on the page referenced in the URL. Did RMS self-censor (unlikely), or ???
[Jay] RMS is a shithead, and now I believe it.
And no, I don't blame Jimmy for this.
[Sluggo] He's right though. When did reading become a "human right" like, oh, the right to practice your religion and not be killed?
Redneck Texan: what in tar-nation are they talkin about, "human right to read"? Next thing y'all know they'll be askin for the right to a mansion on the beach. And that other thing they keep harpin about, that loonie-versal health care whatsit. In my father's day people never asked for a handout, they worked and provided for themselves like God intended.
[Neil] Yep. One quote I agree with. Elevating reading to a human right seems excessive, so unlike RMS, I am not enraged by that particular quote.
I would support the idea of a right to sufficient education to be able to read. I would also support the idea that people have a right to enjoy a book that they have purchased legally and in good faith, but a right to read any book or document you want, regardless of whether it not it's published or confidential is another matter. What would a "right to read" cover and in what circumstances, I would like to know?
If the injunction really orders them not to read the books they have purchased, that strikes me as wrong, but hey, we all know the law is an ass, even in Canada. If I'd bought a book and got an injunction like this, I'd still read it, I just wouldn't tell them
[Ben] ...and if we extend that line of reasoning just a bit further, it brings us to (what I think is) RMS' original point. How much of a right do we grant to our governments to declare arbitrary actions illegal, no matter how trivial or harmless?
The cynic in me says that governments love having their citizens buy into a belief that they (the citizens) are guilty of something; people with something to hide are likely to keep their heads down and be good little sheep lest they be noticed and shorn. As the saying in Russia went, "nobody ever asks 'why' when the KGB takes them away." The KGB, of course, had a matching expression: "if we have the man, we'll make the case."
If the government is allowed to control trivial aspects of people's lives, then they will do so. Not in all cases, but... oh, the "opportunities" that arise. Perhaps this case is not as black-and-white as it could be, but I surely do see it as a very steep and well-greased slippery slope - with its entry point just under a hidden trap door.
[Sluggo] ... which comes back to my original point, that there is also a slippery slope / trap door on the other side. In order to get a diverse coalition of people (the whole world) to agree to and enforce something, it has to be narrowly focused and not arbitraily "reinterpreted". It has long been recognized internationally that people have a right to not be imprisoned/tortured/killed for their ethnicity, religion, or participating in political protests. That's what's normally considered "human rights", and it's why China is under so much scrutiny. Canada and the EU have more inclusive definitions of basic rights, but those apply only in those countries and cannot be summarily exported to the rest of the world as "human rights". China's censorship of the Internet is deplorable but is not (yet) a "human rights violation".
[Ben] [blink] Since when is getting the entire world to ratify something a rational goal? I don't think it's possible - except by the method employed by US politicians and so aptly described by Dave Barry.
............... We make presidential candidates go through a lengthy and highly embarrassing process that a person with even the tiniest shred of dignity would never get involved in. It's analogous to the ice-breaking party game "Twister," wherein somebody spins a pointer, and the players have to put their hands and feet on whatever colored circles it points to, thus winding up in humiliating positions. And the people who want to be president have to play. If the spinning pointer of political necessity points to SUCK UP TO UNIONS, they have to put their left hands over on that circle; if the spinner points to SUCK UP TO RELIGIOUS NUTS, they have to put their right feet in that circle; and so on, month after month, with candidates dropping out one by one as the required contortions become too difficult, until finally there's only one candidate left--some sweaty, exhausted, dignity-free yutz in a grotesquely unnatural pose, with his tie askew and his shirt untucked and his butt crack showing. -- Dave Barry ............... |
The effect is that nobody gets what they want, and whatever agreement is reached is so watered down that it's meaningless - and, as a result, is ignored by everyone. E.g., UN's decisions about Iraq, and damn near everything else since then (and about half of everything since UN's inception.)
[Sluggo] Better to try than to throw up your hands and say it's impossible.
[Ben] Better to try something different and effective (assuming there is such an option) than keeping on with something that has long lost its force.
[Sluggo] So creating the UN and its human rights commission and Geneva convention and ICC et al was a waste of time? I disagree.
[Ben] I would too, if somebody had said what you're implying I've said. The UN was very useful at the time of its creation - despite Russia managing to wangle two seats instead of the one they should have had - but these days, it's a debating society with damn near no force or effect. I've known several people - Canadians who had been with their peacekeeping force - and the strong impression that I got from them was that of despondency, of rolling that same useless rock up that same useless mountain, only to have it roll back down again.
At this point, the Big Guys - US and Russia, and to some lesser degree everyone else - has found their own ways to circumvent or bypass (and in case of serious disagreement, simply ignore) the UN. My contention is that it is no longer useful as a vehicle for maintaining peace or a round table for mediation/negotiation - all of that now goes on at high-level conferences, which were rarer and more difficult to arrange in the days when the UN was created.
[Sluggo] And what were the alternatives? At least the UN has prevented World War III so far (with NATO), which was its main purpose.
[Ben] I think you're giving the UN far too much credit. For one thing, the projections for WWIII are pretty horrific - at least the ones that we had when I was in Military Intelligence - and they're not likely to have improved (<black_humor>except in the kill ratios</black_humor>.) Nuclear deterrent would be the number one cause, in my mind - not in the number of people that are likely to die (why would the politicians care? They never did before), but in the fact that the high-level decision makers - despite their bunkers, etc. - are much more likely to, or are far less likely to survive the aftermath.
Nukes make it personal for them. That, to my mind, is the only thing that will stop them from issuing those orders.
[Sluggo] The UN has been ineffective in stopping the genocides in Rwanda/Bosnia/Somalia/Sudan -- but so were its critics.
[Ben] Errr... so, if I say that a radio doesn't work, my inability to repair it makes my observation false? Please reconsider what you're saying here, Mike.
Amy Chua in "World on Fire" describes, in fine detail, how the US exportation of (some screwed-up version of) democracy plus the free-market system leads to civil wars and murder of economically-dominant minorities. It's damn near impossible to disagree with her data, or the conclusions she draws from it - the lady is quite sharp. However, she doesn't say "...and here's how to fix it!" Does that make her observations inaccurate, or her book of no value? I sincerely doubt it.
[Sluggo] Re Iraq, I can't comment further without the missing piece -- what you think the UN did wrong and should have done. You think they should have supported the US intervention? I think not.
[Ben] I think that the UN did what they could. The overriding issue is that they could do nothing effective, except make their statement for the world to hear - something that is done just as effectively by a protest march in DC. That's not saying a lot for the UN.
Just to add a personal viewpoint here: I find it sad that this is the state of the UN, and wish with all my heart that it did have more effect. But when a rabbit mediates a disagreement between two bears, the effect of that mediation is not likely to be much - and the rabbit is likely to get eaten for his trouble.
[Ben] US and China, for example, have many mutually incompatible goals, long-term plans, and cultural imperatives. Expecting China to agree with the US on human rights is a waste of time - particularly since China is strong enough to not worry about the US in military terms. The human rights issue between the two is, therefore, at a standstill - but Walmart still buys 80%+ of what they sell in China.
Remind me again why China should care about anything the US says?
[Sluggo] The slippery slope is that the more things you pack into this definition, the less willing a lot of people will be to accept the whole thing. For instance, the US administration is reinterpreting free trade and property rights to include perpetual copyrights, anti-circumvention provisions, and software patents.
[Ben] Therefore making itself that much less relevant to the world market. [shrug] If the idiots wielding the broom don't watch out, the tide will sweep them out to sea.
[Sluggo] Now, one could make a case that these should be property rights and included, but instead the administration is bypassing the debate and arguing these are self-evidently property rights. Not surprisingly, there is much resistance in other countries, fears about whether free trade is a synonym for US corporate hegemony, and wonderings about why countries should harm their own vitality to benefit foreign patents. Likewise, there is much resistance in the US to the "right" to living quarters, health care, welfare etc -- this is seen as the foot in the door for socialism, 90% taxation, and burnt work ethic. (Didn't you say something about the KGB?) So, do you want to support basic human rights, or do you want to throw other things in and weaken support for the basic rights?
[Ben] If I thought that was a valid question, it would certainly be a dillema. As it is, I don't see them as mutually exclusive.
[Sluggo] Stallman has made a good case over the years that the right to read anything is fundamental. Obviously, not being able to study holy texts would significantly impact people's practice of religion. So would not having access to news or commentary. And fiction books often express a political view or framework, sometimes more valuable than the author realizes. So it's impossible to censor non-essential texts while excepting essential, because inevitably you will misclassify an essential text.
Still, the extremes to which "free speech" and "free reading" can be taken are ridiculous. Exactly how does suppressing Harry Potter for two days harm Canadians' access to an adequate variety of information?
[Ben] That's not the grounds on which I find the court's decision to be less than intelligent. Trying to enforce something that is fundamentally unenforceable - arrogating to themselves the right to decide that you should voluntarily surrender the value of that for which you have paid - those are the things which set off all sorts of alarms for me. With regard to the adequate information issue, I agree with you - I don't think that this has been violated, or was even involved.
[Rick] It does seem quite an overreaction. Judges in (to my knowledge) almost all countries tend to be a bit sweeping in their application of court orders -- being demigods in their sphere -- and a little sloppy. But, as you say, it was just a two-day featherweight decree, anyway.
Unlike Richard, I decline to pass judgement on our esteemed Canadian neighbours' legal doings, and simply state that I've been quick to help Canadian friends circumvent what they regarded as judicial overreaching in the past, e.g., by sending them US and European news coverage of the Karla Homolka trial.
I happened to be in Alberta recently when Homolka was released from a Quebec prison at the end of her ten-year sentence. The tedious excess of news coverage even in good papers like the Globe and Mail was enough to give even the most stalwart free-press advocate misgivings.
[Sluggo] How does viewing porn -- another example of "free speech/reading" -- enable one to make a better decision on election day or to support a cause?
[Ben] Since when are those the ultimate ends, and why is personal pleasure held to be less important those things? You may have to use words of two syllables or less to explain; I lack the Puritanical programming that most Americans have absorbed, and can't make those connections automatically.
[Jimmy] Now, maybe it's because I witnessed first hand the sort of social improvements that came from pornography being decriminalised, but I find it absurd that anyone who is as interested as you are in things like civil liberties and social equality can even question the importance of porn.
In my teens (and I'm 2 weeks away from my 26th birthday, BTW -- we're only talking about one decade) Ireland had a very heavy-handed Censor's office, which was heavily under the influence of the Church. Anything vaguely pornographic or 'heretical' was illegal[1].
Part of the downfall of this was technology (satellite TV was becoming cheaper[2] and put TV out of the censor's hands), another part was that they went too far -- they banned a newspaper (one of the British tabloids, "The Daily Sport". In fairness, it did have at least one picture of a topless women on every other page, but it also had the best sports coverage of any of the daily newspapers at the time, as well as covering aspects of the news that none of the other papers did).
To come to your point: pornography isn't just something you watch, words can be judged pornographic too. It can help you make a better decision at election time if you can read an uncensored account of what the issues are.
[1] "Life of Brian" was found to be both, among other films. I can't say for certain whether or not there was a direct link between the two, but (IIRC, which is highly unlikely) after the BBC showed that film uncensored, the Irish government started blocking British TV broadcasts, which most people in Ireland had been able to receive.
[2] Every Friday and Saturday night, two of the German channels had porn -- 'Benny Hill'-type stuff with full frontal nudity, but 'shocking' enough for the priests, enticing enough that the price of satellite TV halved within a year. VCRs were still rare around this time.
[Sluggo] And of course, what does that idiot judge think he's doing forbidding people from reading the books they've purchased? Telling them not to talk about it may be reasonable, perhaps, -- there's no right (in the US) to talk about what you hear on police radio bands -- but telling them they can't read a book that's in front of them is... paranoia. Hopefully other Canadian courts will view this as an aberration. Canada has been good about supporting people's rights in general: crypto importing/exporting, recording CDs, and watching foreign commercial satellite broadcasts. And gay marriage and marijuana.... Hopefully they aren't about to turn this around.
What about bomb-making materials? Is there a right to read/publish about those?
[Ben] Why not? It's the locksmith principle: the people who want that access will have it. The only ones who will lose out on the knowledge are the people who can do something positive with it - e.g., the pharmacy clerk who may recognize that someone is buying materials for bomb-making and act appropriately.
............... "In respect to lock-making, there can scarcely be such a thing as dishonesty of intention: the inventor produces a lock which he honestly thinks will possess such and such qualities; and he declares his belief to the world. If others differ from him in opinion concerning those qualities, it is open to them to say so; and the discussion, truthfully conducted, must lead to public advantage: the discussion stimulates curiosity, and curiosity stimulates invention. Nothing but a partial and limited view of the question could lead to the opinion that harm can result: if there be harm, it will be much more than counterbalanced by good." -- Charles Tomlinson's Rudimentary Treatise on the Construction of Locks, published around 1850. ............... |
[Sluggo] Let's not forget companies' (self-proclaimed) free-speech "right" to send you spam.
[Jay] But let's be clear here. The right to exploit commercially the effort which was put into that novel belongs to the author and her publisher, and I see no reason why they should be forced to exercise that right in any way other than the way they want.
And leaking the spoiler, assuming that was really in RMS's original (which wouldn't surprise me in the least, given RMS's behavior in the past), was simply childish.
How apt.
From Jimmy O'Regan
XML Acronym Demystifier, to expand your collection http://www.xml-acronym-demystifier.org
[Rick] I am reminded, inescapably, of The Parable of the Languages: http://weblog.burningbird.net/archives/2002/10/08/the-parable-of-the-languages
[Ben] Heh. Thanks, but my list is all about commonly-used Net/email/Usenet acronyms; I don't think the XML bunch will cross with any of that.